A phone app made for keypad phones – the Qin F21, Dumber Mini, Doov R77 Pro and other small Android phones with a D-pad and a T9 keypad. Dialing, the call history, contacts and the calls themselves work with the keys alone: the digits start dialing right away, the green key calls, and the call screen is a row of buttons you move through with ← / →. There are no floating buttons, no swiping and no on-screen dialpad, and the layout fits a 480×640 screen.
It's built on Fossify Phone, and its contact lists look and behave like DumberKit: Contacts. Touch is switched off inside the app, so nothing gets pressed by accident in your pocket.
The app opens on the call history with the newest call selected, ready for the green key. The three tabs – Call history, Contacts and Favorites – are icons at the bottom; ← / → switch between them and every tab starts at its first row.
| Key | What it does |
|---|---|
| 0–9 | Start dialing a number with that digit |
| Call (green key) | Call the selected call or contact (nothing selected: the dialer) |
| OK | Call history: call back · Contacts: open the contact in DumberKit Contacts |
| Hold OK | Actions: call, send SMS, add to / remove from favorites, edit, block, delete… |
| # | Send an SMS to the selected number or contact |
| * or the Ab button | Jump to a letter in the contacts (A–Z grid, the keys 2–9 jump like on the keypad) |
| ↑ on the first row | The top bar: jump to letter, search, dialpad, menu |
| Menu | New contact, sort, filter, clear the call history, settings, about |
| Back | Jump to the first row; Back again leaves the app |
Search, Ab and * always look for contacts. Started from the call history, the history stays on screen while you type or pick a letter, and the contacts show up once you confirm with OK.
The digits type the number into a big field on top, next to a handset and with a blinking cursor; the contacts whose number or name matches it (T9, so 62 finds Mama and Martin) are listed below. No on-screen dialpad and no keyboard get in the way.
| Key | What it does |
|---|---|
| 0–9, *, # | Type the number |
| Call or OK | Call the number (or the selected contact); with nothing typed it puts in the last dialed number |
| ↓ / ↑ | Pick one of the matching contacts |
| Back | Delete the last digit; with nothing typed it closes the dialer |
| Hold Back | Delete the whole number |
| Hold 0 | + for international numbers |
| Hold 2–9 | Speed dial |
| Menu | Pick the SIM, add to contacts, send SMS, add a pause or a wait, speed dial numbers |
A contact's photo (when the contact has one) sits in the middle, Answer on the left and Decline on the right.
| Key | What it does |
|---|---|
| Call, OK or ← | Answer |
| → | Decline |
| Back | First press: silence the ringing · second press: hide the screen, the call keeps ringing silently |
Opening the app while a call rings brings the call screen back. On phones where the red key is the power button, Android only silences the ringing with it.
On many keypad phones the arrows ↑ / ↓ set the volume during a call, so the call screen uses a row of round buttons instead: ← / → pick one, OK uses it, and its name and state are shown underneath (Speaker: On).
| Key | What it does |
|---|---|
| ← / → | Speaker, mute, hold, add call, hang up (swap and merge with two calls) |
| OK | Use the selected button |
| 0–9, *, # | Send tones, for automated lines |
| Call (green key) | Turn the screen off; green or Back turns it on again |
| End (red key) | Hang up – with the screen on and Android's Power button ends call switched on |
Phones with a proximity sensor switch the screen off at your ear by themselves. Many keypad phones have no such sensor, so the screen stays on at your ear. With Turn the screen off during calls the app switches it off 2 seconds after the call starts (for an incoming call once it is answered), and the ear can't touch anything. Android only lets apps do that as a device admin: the app asks for it once, uses it for nothing else, and the switch in the settings removes it again. Without it the screen only dims after 10 seconds.
Every option is a row you can reach with the arrows, the lists open as dialogs with the current choice selected.
- Allow touch input – off by default.
- Turn the screen off during calls – the device admin described above; only on phones without a proximity sensor.
- The usual Fossify options: blocked numbers, date format, font size, name order, number formatting, tabs, grouping of subsequent calls, call confirmation, dialpad vibration and sounds (off by default), speed dial, exporting and importing the call history.
- Colors – System (follows Android), light, dark and other themes; the app icon is green by default and any other color can be picked.
- About – the version and the keys of every screen.
- Language – on Android 13 and newer the app's own language can be picked; it comes in over 50 languages from Fossify's translations, the keypad texts are in English and Slovak.
- Download
dumberkit-phone.apkfrom the latest release. - Open it on the phone and allow installing apps from that source when Android asks.
- Start Phone with the green icon, let it become the default phone app and allow access to the call history and contacts.
- On phones without a proximity sensor allow Turn the screen off during calls when the app asks (it can also be switched on later in the settings).
Requires Android 8.0 or newer.
The green key on the home screen: on many keypad phones the green Call key opens the phone app from the launcher. If on your phone it doesn't open DumberKit Phone (nothing happens, or the old phone app opens), map the Call key to open Phone with Key Mapper or a similar app.
./gradlew assembleFossReleaseThe release build is signed with the key from keystore.properties (see keystore.properties_sample), the APK ends
up in app/build/outputs/apk/foss/release/.
DumberKit: Phone is free software under the GNU General Public License v3.0.
The core of the app is Fossify Phone and its Commons library (GPL-3.0) – calling, the call history, blocking, themes and translations come from there. DumberKit: Phone is a modified version, reworked in 2026 for keypad navigation and small screens. Thanks to the Fossify team and its translators.