For the Nothing Phone (4a) Pro
The back of your phone, finally smart.
Agent Glyph turns the round light panel on the back into a private, living display. A bold clock by default, and whatever matters the moment it matters: a secret glyph for the person calling, music that moves to the beat, the next turn. Tap it or shake it. No screen needed.
Planned price $4.99 · Not in any store yet · Not made by Nothing
Try it
Tap it. Shake it. Ring it.
A virtual back of the phone, running the app's own faces. Double tap for the next face, shake for more, or let Alex call.
Clock
01 Smart Face
Never blank. Always the thing that matters.
Left alone, the back shows a clear, bold clock. When something matters, it takes over by itself, and when it's over, it crossfades back. You choose what it rests on.
The clock: bold digits you can read at a glance.
- Calls
- the caller's glyph, or a generic call symbol
- Google Maps
- the next-turn arrow and distance
- Music
- a visualizer that reacts to the actual sound
- Charging
- a filling ring with the charge level
- And
- a focus timer, a meeting about to start (optional), low battery, and an optional very dim night clock for the bedroom
02 Secret glyphs for your people
A custom ringtone, for the lights.
A heart is my partner. Only I know that.
Alex is calling
Choose someone
Pick a person from your contacts. The app gets only that one name. It never reads your contact list.
Give them a glyph
Pick a ready-made glyph, a letter or two, or draw one on a pad shaped like the panel.
Choose when it plays
Calls and messages, calls only, messages only, or everything that mentions them.
When they call, their glyph plays on the back. Strangers get a generic call symbol, and unknown numbers stay hidden by default. A shake shows the caller's name for a few seconds.
Try it before anyone calls: Show on the back previews a glyph, and Try a call rings the back as if that person were calling.
- Alex
- Sam
- Mum
- Jo
- Anyone else
03 Music you can see
It moves to the real music.
Agent Glyph listens to what your phone is playing, finds the beat and the tempo, and splits the sound into 12 frequency bands. Four styles are designed for the round panel, with deep darks and only a few brightness levels. About 30 frames a second, measured on the phone.
-
Pulse default
A core that swells with the bass, and a ring that bursts to the edge on every kick.
-
Ring
A radial spectrum around the disc.
-
Bars
A mirrored spectrum growing from the middle.
-
Stars
A starfield that speeds up with the energy.
Shake to see the song. A shake shows the title and artist.
Microphone, only if you want it. It's asked for only when you switch on hear the music: to see the beat, not to record. Nothing is kept or sent. Say no, and a gentle beat-less animation plays instead.
04 Tap and shake
No buttons. No screen.
Double tap the back to switch to the next face, or to the next visualizer style while music plays. It works with the screen off, even on a table. Shake is the universal "tell me more".
| Showing | A shake shows | Try it |
|---|---|---|
| Clock | date, battery %, next alarm | |
| Music | song title and artist | |
| Charging | watts and charge, e.g. "27W 64%" | |
| Call | the caller's name | |
| Maps | the next turn and distance | |
| Sun / moon | sunrise and sunset / moon % | |
| Timers | exact time left |
- 19/21 real double taps recognised
- 15/16 with the screen off
- 0 false triggers in the recordings from put-downs, handling, typing or shakes
Tuned from recordings of real use through a phone case. A small tick on the rim when a tap is heard, then a flash and a light buzz when a gesture counts. Sensitivity: soft, normal or firm.
05 A library of faces
Pick what the back rests on.
Every face below is the app's own drawing, frame for frame. Tap the big panel for the next face, or shake it to see what it knows.
Clock
The time, bold.
Clock
Clock, Night, Hour, Analog, Day ring, Date, World clock
Status
Battery ring, Next alarm, Meeting countdown, Focus timer, Countdown to a date
Sky
Sun on its arc for your city, tonight's Moon
People
Glance: the glyphs of people with unread messages
Data
A URL face for a number, text, progress or an icon from any web address, with a weather template that needs no account or key
Art
Glow, pixel art, and anything you draw or import. The pad imports and exports the community's Glyph Matrix design formats.
06 Privacy
Everything stays on the phone.
No account and no cloud. Agent Glyph runs on your phone, and nothing it sees leaves it.
Contacts are never read
You pick one person at a time through Android's contact picker.
No call-log access
No phone-state or call-log permission. The caller's name comes from the call notification.
Microphone, optional
Only to see the beat. Nothing is recorded, stored or sent.
Calendar, optional
Only for the meeting countdown. Meeting titles stay hidden unless you turn them on.
Almost no network
Only the optional URL and weather face, and the local API, which listens on the phone itself.
No Nothing SDK
The app talks to the phone's Glyph service directly. No third-party SDKs at all.
Every permission, and why
| Permission | Why | Asked when |
|---|---|---|
| Glyph service access | to draw on the panel | at install (normal) |
| Notification access | callers, messages, Maps, music, counts | in the app's setup; you grant it |
| Microphone | beat detection for the visualizer | only when "hear the music" is switched on |
| Calendar | the meeting countdown face | only when that face is picked |
| High-rate motion sensors | detect taps through a case | at install (normal) |
| Vibrate | a haptic tick on a gesture | at install (normal) |
| Internet | the local API and the optional URL face | at install (normal) |
| Foreground service, boot, notifications | keep the display running and restart after a reboot | at install (normal) |
07 For developers and AI agents
Anything on the phone can draw on the back.
A local web API on 127.0.0.1:8765 and a glyph command. Show text, scrolling messages, pixel art, animations, progress and faces, or change any setting. It listens only on the phone itself.
# the glyph command
glyph text "tests passed: 128/128"
glyph anim --value 60 progress
glyph face analog
glyph music bars
glyph focus 25
# or plain HTTP, from anything on the phone
curl -X POST 127.0.0.1:8765/text -d "deploy done"
curl -X POST "127.0.0.1:8765/animate?then=clear" -d check
curl 127.0.0.1:8765/frameClaude Code, on the back of your phone
Hooks let the panel mirror an AI coding session: thinking, working, needs your attention, done. Glance at the back and know whether it's waiting for you.
glyph event done # what the hook sends
glyph assign done anim:burst # what you'd like to see
glyph assign attention text:HEY
Gesture Lab
A companion app: record a gesture ten times, and it learns it, checks it against your other gestures and your everyday movement, and refuses gestures that would misfire.
Glyph Racer
A bonus: a tilt-to-steer racing game played on the 13 by 13 panel.
Under the hood
Native Android (Java) with no third-party SDKs. A compositor decides what shows: call and navigation, then agent messages, then music, charging and notifications, then your face. Gestures run on 400 Hz motion rules learned from real recordings, at about 3% of one CPU core while sensing.
08 Get started
Four steps, all on the phone.
Install and open
The Setup screen walks through each grant, with its state and a button that fixes it.
Turn on notification access
For callers, messages, Maps and music.
Choose the always-on toy
In Nothing's Glyph Toys settings, pick Agent Glyph as the always-on toy, so the back keeps working with the screen off.
Make it yours
Pick a face, give your favourite people a glyph, and play some music.
Coming soon
$4.99 planned price
- Every face, style and gesture
- Secret glyphs for as many people as you like
- The local API and the
glyphcommand - No account, no cloud
Built and tested only on the Nothing Phone (4a) Pro with Android 16 (Nothing OS 4). Other Glyph Matrix phones are unverified. Not in any store yet.
Hear when it launches
One email when Agent Glyph is available. Nothing else.
09 Questions
FAQ
Which phones does it work on?
The Nothing Phone (4a) Pro on Android 16 (Nothing OS 4), with its 13 by 13 round Glyph Matrix of 137 LEDs. It hasn't been tested on any other phone, so we don't claim it works there.
Is Agent Glyph made by Nothing?
No. It's an independent app, not affiliated with or endorsed by Nothing. It talks to the Glyph service the phone already has.
Does it need an account or the internet?
No. Everything runs on the phone. The only network use is the optional URL and weather face, and the local API, which listens only on the phone itself.
Does it read my contacts or record audio?
No. You pick one person at a time, and the app gets only that name. The microphone is optional and used only to see the beat: nothing is recorded, stored or sent.
Does it work with the screen off?
Yes, once Agent Glyph is chosen as the always-on Glyph Toy. Faces then show at full brightness, except the night face, which stays dim on purpose. Note that Nothing's system dims every always-on toy to a quarter of its brightness, and briefly shows its own notification light over any toy.
The back was dark after I installed an update. Why?
After installing or updating, the first screen lock can be dark until the screen has been on once, because Nothing's system reconnects the always-on toy late. Lock, unlock and lock again, and it's back.
Can I use designs from other Glyph Matrix tools?
Yes. The drawing pad imports and exports the community's Glyph Matrix design formats, so designs made elsewhere play here, and yours play there.
Is it finished?
It works every day on the developer's phone and is being polished. A few things are still being proven in real life: a real incoming call from another person showing their glyph with shake-to-reveal from start to finish (a real call has shown the caller's name), the charging ring while actually plugged in, and the night face's final dim level.
When can I buy it?
It isn't in any store yet. Leave your email above and you'll hear once, when it is.