How it works

An Echo is a memory time capsule fastened to a place. One Echo can hold several photos, a video, a voice memo, a 360° panorama, and a written reflection — or any combination. The Echo lives at the latitude and longitude where you left it.

Open it and the pieces replay as a story: photos move through in sequence, your voice plays over them, video and panorama follow. Many photos from the same event — prom night, a trip, the day the baby came home — gather into a single Echo on one pin, not scattered across the map.

Walking back to that spot, or tapping the pin on your map, opens the moment again. The product’s job is to make that return feel like stepping into a place you knew.

Three paths in, depending on where you’re starting from.

In the moment, on the spot. From the home page or the map, tap Leave an Echo. The composer opens, your phone’s GPS sets the location, and you have four capture tiles: a photo, a video clip, a 360° panorama, a voice memo. Add what you want — a title, a reflection, an audience, an optional time-lock — and tap Leave it here.

From your camera roll, one rich Echo at a time. On the home page, tap Build an Echo → Build one Echo. You can pick multiple photos for a single event (prom night, a trip, the day the baby came home) and choose which one is the anchor — that’s the photo that sets the map pin and starts playback. Same title + reflection + media slots + audience + seal controls as the composer.

From your camera roll, many at once. Build an Echo → Build many Echoes bulk-imports a batch where each photo becomes its own pin. Photos with EXIF location land where they were taken; photos without get planted at your current location and flagged with a small needs pin badge — open them later from your Echoes and use the Re-pin button on the edit page to drop them where they actually belong.

A note on voice memos. Voice doesn’t live in your camera roll; both the composer and Build-one have an inline recorder. Tap the Voice tile, hit Record, talk, save. Ninety seconds is the cap.

An Echo can hold more than one photo. The first photo — the anchor — sets the map pin and starts playback; the rest follow as additional frames. If those additional photos carry their own EXIF GPS, they become satellite pins on the map, linked to the anchor by a connector line. A trip across multiple stops shows the whole journey, not just the start.

On the build form, the anchor is the large preview at the top. Tap Set anchor on any other photo to swap it in — the previous anchor drops into the smaller grid. Tap Add more photos to pick more from your library. Free plan caps each Echo at three photos; Pro lifts the cap.

360° auto-routing. If you pick a panorama in the photos grid, the form detects the shape (true 360° sphere or iPhone Pano sweep) and moves it to the dedicated 360° slot — so playback opens in the right viewer instead of stretching the image as a wide still. See Stepping back in for the playback behavior.

Already saved an Echo and want to add more photos or swap the anchor? The edit page handles both — see Editing an Echo.

Drop an equirectangular 360° photo into the dedicated 360° slot in the composer (or the edit page) and playback opens it in a real spherical viewer — recipients can drag to look around, pinch to zoom in. iPhone “Pano” sweeps are recognized too and render in a horizontal-scroll viewer that feels natural for that capture mode.

Pro: chain panoramas into a tour. Open any Echo’s edit page and tap Build a 360 tour. Add multiple equirectangular scenes (Trail Head, Living Room, Back Porch, whatever). Each scene gets a name, a starting view, and optional hotspots — small markers that, when tapped, jump the viewer to another scene. The result feels like a real-estate virtual tour, but for memories: walk through a property, a hike, a wedding venue, the inside of a building you’ll never see again.

Auto-place from GPS. If your 360 camera writes GPS tags (most do — Insta360, Theta, Photo Sphere, drone-mounted equirect rigs), the tour builder extracts the coordinates on upload. Inside any scene with GPS, a ✨ Auto-place button appears that drops a hotspot toward every other scene at the geo-computed bearing. If the placements look rotated wrong (drone exports often skip the heading tag, which the math needs), use the Rotate all hotspots buttons below the viewer to align them once; future Auto-place calls on that scene then land correctly out of the gate.

Map treatment. Tour scenes with GPS pin individually on the map, with a connector line tracing them in scene order. A multi-stop tour shows the journey at a glance.

Capture the starting view. For each scene, drag the preview to the framing you want recipients to land on first, then tap Set start view. The tour opens that scene with that yaw / pitch / zoom every time.

A reflection — the words you write into an Echo — can play as plain text on a quiet background, or as a stylized first frame with custom typography, layout, and imagery. Pro feature.

In the composer, the Reflection style row shows a carousel of presets. Tap one to stamp it on this Echo; tap the default (plain text) to clear it. The style applies to the very first frame the recipient sees — before any photos — and sets the emotional tone. Pride, Nostalgia, Wonder, Stillness, Longing, Fury, Legacy, Love: the preset titles map to the emotional palettes available.

Custom presets are managed in the admin Reflection builder — fonts, layer-based composition, position grid, custom background images. Each saved preset becomes a chip in the composer for everyone on Pro.

Attach a piece of music to an Echo and it plays softly under the whole story arc — under reflection, photos, video, voice, panorama. It ducks automatically during video and voice recordings so the foreground audio reads clearly, then comes back up for the photos and panoramas. Pro feature.

In the composer, the Music row lists the curated tracks available. Pick one (or none — silence is also valid). The choice rides with the Echo, so a burn-link recipient hears the same music you chose.

The library itself is curated by the admin via Music library — upload mp3 files, set names, per-track volume offsets. Tracks loop on their own; the player handles fade-in, fade-out, and the duck levels.

Every dot is an Echo. The color of the dot is the color the author picked for themselves (or the color you chose for that person — see marker color & overrides).

The map remembers where you were last looking. When you tap an Echo and come back, the camera is where you left it.

Use the layers button to switch between Satellite, Standard, Dark, and Terrain. Use the filter button to toggle audiences (Mine, each of your groups, Public). Your preferences persist across sessions.

Drag to re-pin. Your own dots are draggable. Long-press on touch, click-and-drag on desktop — drop somewhere new and confirm. The Echo’s pin and its anchor photo’s coordinates both update. (Echoes that share a spot with another within ~25m become a cluster and aren’t individually draggable — use the edit page if you need to nudge one of those.)

Every Echo starts Only me. That’s the default. Nobody else can see it — not the people in your groups, not the public, not anyone.

When you leave one (or edit it later), you can grant view permission to any subset of the groups you belong to, and independently flag it as Public (anyone on the map can see it). You can pick more than one group; you can pick none.

Groups are viewports, not destinations. Nobody “posts to” a group — Echoes always belong to the author. The author decides which lenses to show them through.

You can own up to six groups. Family, friends, co-workers — name them whatever you want. You decide who’s in each.

Roles inside a group:

• Owner (you, for groups you created) — rename, delete, add/remove members, assign admin.
• Admin — add and remove members. Cannot rename or delete the group.
• Member — view-only. Can mute their own whisper for the group, can leave the group.

Being a member of someone else’s group does not count toward your six owned-group slots.

To invite, type a phone number (or pick from contacts on Android). The person is “Pending” until they sign up — tap the Text button on their row to send them the link from your own Messages app. When they sign in with the invited number, they’re joined automatically.

Flagging an Echo Public means anyone with an account can see it on their map — including people in your groups (Public encompasses them all).

On the map filter, Public is off by default. You only see Public Echoes from strangers when you toggle it on. Same for everyone else looking at your Public Echoes — they choose to look.

When you walk within 50 meters of an Echo you have access to, the app whispers — a quiet card surfaces on the map and (if you’ve allowed it) a push notification fires.

Whispers respect your settings:

• Your own Echoes always whisper.
• Group-shared Echoes whisper only when the granting group is unmuted on your end. Each group you belong to has a Mute / Unmute toggle on its card.
• Public Echoes from strangers don’t whisper. Public is for looking, not for being notified.

An Echo is a seed, not a post. Anyone who can see one of your Echoes — group members or the wider audience, depending on how you shared it — can add a memory to it.

That memory becomes another frame in the Echo’s playback. Your sister adds her recollection of the recipe card. Your uncle adds a voice memo about the kitchen it was written in. Your daughter, twenty years from now, adds her own reaction to the whole thread. Only the people who can see the Echo can see the memories on it. Group-shared Echoes have group-private memories. Public Echoes have public ones. The audience never widens — it only deepens.

During playback, after you’ve sat with an Echo for a moment, a quiet “Add to this Echo” button fades in. Tap it, write what you remember, save. It joins the story.

Your words are your own. Only you can edit a memory you wrote. If you’re viewing your own contribution, a small pencil appears on the frame — tap it to revise or delete.

The Echo’s author curates, never rewrites. If you own the original Echo, the edit page has a Memories on this Echo section. You can silence a memory (hide it from playback without destroying the contributor’s words) or delete it entirely. You cannot edit someone else’s words. Their voice is theirs.

Any Echo can be sealed until a date. Inscribe today, set the unlock for your kid’s 18th, your tenth anniversary, the morning you get home from deployment. Until that date, recipients see a sealed pin on their map with the unlock date — no media, no body, no title leak.

You always see your own sealed Echoes through the seal, so you can verify and edit them up until the date. The seal is the actual Æternum feature — leaving a moment for a moment that hasn’t happened yet.

On the composer or the edit page, look for 🔒 Seal until a date…. The control includes a countdown (“ignites in 2 years, 3 months”) so you can see what you’re committing to before saving.

If you have many Echoes anchored at home, walking to the kitchen shouldn’t whisper at you. The quiet zone is a circle (default 150m) where whispers stay off.

From your profile, tap Mute whispers at my current location. Move it later if you set it from the wrong spot.

You pick your own marker color from a palette of eight. By default, everyone in your groups sees your Echoes in that color.

But you can override what you see for each person you know. On any member row in a group, tap the pencil → write a label (“Mom,” “Sara”) and pick a color. That’s how that person appears on your map only. They’re unaffected.

This is also how you avoid color conflicts. If you and your wife both pick the same color, you can override hers on your map without a coordination conversation.

Tap any Echo to enter playback. The Æ ignites briefly, then the story plays frame by frame — text first, then the anchor photo, then any additional photos, then video, then 360°, then voice. Frames advance with a tap on the right half of the screen or a left-swipe. Tap-and-hold pauses auto-advance.

Tap a photo to expand it full-screen; tap again (or the × in the corner, or Esc) to shrink back. Video has native controls.

Panoramas. True 360° spheres (Insta360, Theta, Google Photo Sphere) open in Pannellum — drag to look around in any direction. iPhone Pano sweeps and other cylindrical panoramas play in a horizontal-pan viewer — drag side to side to see the full sweep. The right player is chosen for you based on the shape of the file.

Multi-photo Echoes. Each photo is its own frame. Frames carrying their own EXIF location show a small pin badge in the corner so you can tell “this part of the story was over there.”

You can save any photo or video to your phone via the Save button under the media. On iOS the share sheet lands it in Camera Roll; on Android it goes to Photos. The Echo stays where it is — saving is just for you.

Echoes you didn’t leave yourself show Left by [name] above the title — using the label you picked for that person, or theirs if you haven’t overridden.

To change anything about an Echo — title, media, audience, seal date, even location — tap the small ✏️ on the playback chrome at the bottom (or in your Echoes list, the pencil on each card). See Editing an Echo for the details.

The edit page is the curatorial side of an Echo. Open it from any playback view (the small ✏️ in the bottom chrome) or from your Echoes (pencil on the card). It has the same shape as the build form: Words, Photos, Capture, Audience, Time lock — plus a few edit-only sections.

Re-pin the location. The “Editing Echo at” card up top shows the address (reverse-geocoded from the coordinates) with raw lat/long as a quieter second line. Below the form, the Location card has a Re-pin button that opens the map dialog. Type an address or place name in the search box — results drop down, tap one and the map flies there. Pan to fine-tune, then Pin here.

Swap the anchor on a multi-photo Echo. Each additional photo shows a star icon next to its trash. Tap the star → that photo becomes the new anchor (playback’s first frame, the EchoCard thumbnail, the map pin’s photo). The previous anchor swaps into the slot the new one vacated.

Memories layered on by others. If anyone in your audience has added a memory, they’re listed below the form. You can silence a memory (hide from playback without destroying the contributor’s words) or delete it (remove entirely). You cannot edit someone else’s words. Their voice is theirs. See Memories on an Echo for the principle.

Bulk-imported “needs pin” Echoes. If you imported via Build many Echoes and some photos lacked EXIF GPS, they landed at your current location and show an amber needs pin badge on their EchoCard. Open them, hit Re-pin, drop them where they actually belong. The badge disappears once the location is corrected.

AI helper. The Words section has two chips when you’re on Pro and the Echo has a photo: ✨ 3Q and ✨ Write. See How AI prompts work.

On Android, Echo Æternum appears in the OS share sheet. Open any photo in any app → tap Share → pick Echo Æternum → the composer opens with the photo pre-attached and (if the photo carries EXIF GPS) pre-pinned where it was taken.

iOS Safari doesn’t expose installed PWAs in the share sheet — that’s an Apple-side gap, not a setting we can flip. On iPhone, the path is: open Echo Æternum → Build an Echo → pick Build one Echo or Build many → pick the photo(s) from your library. The EXIF location comes through either way.

Sometimes the right thing for a moment is to share it with one person who isn’t on Echo Æternum — a grandparent, an old friend, the recipient of a long letter. The Burn Link is for that.

Pick an Echo, tap Burn Link (on the edit page, or in the three-dot menu on the Echo itself), write a short personal note, and tap Generate & Send via Text. Your phone’s share sheet (or SMS composer) opens with your note and a URL pre-filled. They tap it, the Echo plays full-screen — no account, no install, nothing to set up on their end.

It lasts twenty-four hours. After that, the same URL flips to a quiet page that shows your note and a prompt to ask you for an invite for eternal access. From there it’s the normal group-invite flow on your end.

Optional: invite them into the group this Echo lives in. When you generate the link, you’ll see a checkbox for each of your groups the Echo is shared with. Leave it checked and the recipient gets a one-tap “Get added to [Group]” button on the page. They enter their number, the next sign-in lands them inside your group — no SMS step on your end. If the Echo is private to you (Only-me), there’s no group to offer; the sheet says so. Add the Echo to a group first if you want this path.

A few things worth knowing:

• Burn Link is a Pro feature. The card stays visible on the free tier so you can see what it does.
• Sealed Echoes can’t be shared this way. A seal means “not yet” — exactly the opposite of a Burn Link.
• The recipient sees only the Echo you sent. Not your other Echoes, not the memories your family layered on this one — just the moment, with your note above it.
• “Burn” means the page goes dark, not that we delete the bytes. After twenty-four hours the page no longer surfaces the photo, voice, or video. Files on our CDN may remain reachable to anyone who saved a direct URL during the window. The tombstone copy says this honestly.
• The URL is forever. The tombstone stays at that address, so a recipient who returns weeks later still sees your note and the path to ask for an invite.
• The twenty-four-hour window is fixed in this version.

Quick Burn from /echoes. If you just want the link on your clipboard and don’t need to write a note, every Echo row on Your Echoes has a small flame icon next to the AI chips. One tap generates the link and copies it. No sheet, no message, no group invite — paste it anywhere you want.

Two distinct flavors, both Pro-only. The model never writes Echoes on its own — it asks the question that turns a passive viewer into someone whose hand is on the pen. That’s the whole principle.

Whisper questions (one sentence)

Three contexts, same shape — a single italic question that fits in one breath. Each is admin-tunable per variant; the rest of the section describes the user-side behavior.

• Capture-time — When you’re on the composer or Build-one with a photo attached and nothing else typed yet, a question streams in above Save. Tap Add a reflection to expand it into a textarea pre-placeheld with the question. Type the answer; on Use this the answer becomes the Echo’s reflection.
• Return-visit (dwell) — When you walk back into an Echo’s whisper radius, playback offers a quiet question keyed to that specific moment.
• Adding a memory (layer) — When you’re about to add a memory to someone else’s Echo, the prompt leans outward — it asks for what only you can bring.

Draft helper (title + reflection)

On the Words section of Build one Echo and the edit page, you’ll see two chips when an anchor photo is attached:

• ✨ 3Q — opens a sheet that asks you three questions about the moment (who, what was happening, what’s the part the photo will miss), then composes a title + reflection from your answers. You can edit either in the sheet before tapping Use this.
• ✨ Write — skips the questions and drafts a title + reflection in one shot from the photo and whatever text you already have. Useful when you already know the gist but want help shaping it.

The draft helper opens on the edit page (because it needs an existing Echo to reason about). Build-one’s chips save the form first, then route to edit with the helper sheet already open — feels like one action.

Honest about the draft

When you accept an AI-drafted reflection, the Echo quietly remembers it was AI-drafted. Clear the reflection box after using a draft and the Echo treats the words as fully yours — clearing is the same as discarding the draft.

What we send to the model

The photo(s), the Echo’s coordinates, the date and time of capture, your home ZIP (if set) to compute a rough distance-from-home, plus a couple of small derived signals (whether you’ve been near this spot before, whether the Echo was part of a multi-day trip, what groups it’s shared with for the layer variant).

What we don’t send

Your name, your phone, your other Echoes’ text or voice content, your contacts, the identities of group members, or anything from other people’s Echoes. Faces in photos are not recognized. The model provider does not use this data to train their models.

How to turn it off

Each group has an AI prompts toggle in its settings (owners and admins can flip it). Off → Echoes shared into that group stop showing prompts. For an Echo you want fully off, set its audience to Only me or share it with a group whose toggle is off. The AI helper as a whole can also be paused across the entire app from inside — if you ever notice prompts have gone quiet, that’s why.

Your account is your phone number. Sign-in is one-time text codes; we never store your password because there isn’t one.

Echoes, groups, memberships, and permissions live in our database. Media — your photos, voices, videos, panoramas — is stored on our servers and served back only to you and the audience you chose.

We don’t use your Echoes for advertising. We don’t train models on them. Sharing rules are enforced at the data layer, not just in the app — there’s no client trick that exposes a private Echo.

The hardest question any legacy app has to answer is: what happens to my memories if you go away? Every other answer is half an answer. Lifetime subscription? You still depend on our servers. Family inheritance? Same dependency. Open data export? Usually a CSV nobody can actually use.

Our answer is the Downloadable Echo Viewer. A one-time purchase generates a single folder. The folder contains every Echo you’ve made, every memory layered onto them, your maps, your media — plus a fully functional viewer that runs entirely off the disk.

Drop it on a USB stick. Email it to your kids. Burn it to a disc. Twenty years from now, your grandchildren can double-click it on whatever computer they own and the Echoes play. Same brand, same playback, same maps. No login. No network. No dependency on us still being here.

That artifact, once delivered, cannot be taken back. We can shut down. You can stop paying. Life can do what life does. The folder still works. That’s the covenant.

Pricing and availability launching soon. Watch this section.