Calculator

com.dumberkit.calculator
by Zapstore _@zapstore.dev

Calculator and unit converter for keypad phones, typed on the keypad

Republished from GitHub / F-Droid by the Zapstore main account.

A calculator and unit converter for keypad phones like the Qin F21, Dumber Mini or Doov R77 Pro. There are no on-screen buttons: you type the calculation straight on the keypad and press OK for the result. Touch is switched off inside the app, so nothing gets pressed by accident in your pocket. **Keys** • 0–9 – type numbers • * – add an operator, press it again for the next one (+ − × ÷) • Hold * – a palette of symbols laid out like the keypad: ^, √, parentheses, %, ± • # – decimal point • OK or Call – show the result • Back – delete the last character; hold it to clear everything • ↑ / ↓ – go through the history • ← / → – switch between Calculator, Unit converter and Settings **Features** • The usual order of operations and exact decimals (0.1 + 0.2 = 0.3) • History like a paper tape, cleared when you close the app • Unit converter for length, area, volume, mass, temperature, time, speed, pressure and energy, in both directions • Copy the result, or take a converted value over to the calculator • System, light, dark, dark red and custom themes, a keypad-friendly color picker, blue or any other icon color • No ads, no tracking, no internet access Based on Fossify Calculator (GPL-3.0), keypad input inspired by Calc-U-Later.

First release: Oct 10, 2026, 2 total releases.

Most recent release: Oct 16, 2026.

Repo

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0 sats / 0 zaps received in the past year.

Sats Received

Underlying data available via MCP: app_zaps, app_releases.

Zap Count

Underlying data available via MCP: app_zaps, app_releases.

Releases

  • Oct 16, 2026 1.1.0
    DumberKit: Calculator gets a currency converter. **New** - Currency tab before the settings (dollar and yen icon): about 30 currencies at the reference rates of the European Central Bank, with the same two rows and keys as the unit converter – digits and `#` type the amount, ↑ / ↓ pick the row, OK lists all currencies, `*` swaps them - The rates are downloaded when you open the tab and the ones on the phone are a few hours old, or from the menu; nothing runs in the background. Offline the converter keeps working with the last rates, a copy that comes with the app covers the very first start. The line under the converter shows when the rates were downloaded - The app now asks for internet access – used only to download the ECB's rates **Fixed** - The warning "You are using a fake version of the app", which showed up now and then, is gone - The selected button in dialogs is much easier to see
    More…
    - On phones with an on-screen navigation bar the tabs and the last rows of About stay above it Install `dumberkit-calculator.apk` over the previous version, your settings stay. Requires Android 8.0 or newer.
  • Oct 10, 2026 1.0.0
    The first public release of DumberKit: Calculator – a calculator and unit converter for keypad phones (Qin F21, Dumber Mini, Doov R77 Pro and similar), built on Fossify Calculator. No on-screen buttons: you type the calculation straight on the keypad. **Highlights** - Digits type numbers, `*` adds an operator and turns it into the next one (+ − × ÷), `#` is the decimal point, OK or the green Call key shows the result - The usual order of operations and exact decimals (10 − 2 + 3 = 11, 0.1 + 0.2 = 0.3) - Hold `*` for a palette of symbols laid out like the keypad: powers, square roots, parentheses, percent, ± - History like a paper tape, ↑ / ↓ go through it; it's cleared when you close the app - Calculator, unit converter and settings in tabs switched with ← / → - Unit converter for length, area, volume, mass, temperature, time, speed, pressure and energy, in both directions - System, light, dark, dark red and custom themes; blue icon by default, any other color can be picked
    More…
    - Touch is off inside the app so nothing gets pressed by accident (can be turned on in Settings) - Small (3.2 MB), no ads, no tracking, no internet access Download `dumberkit-calculator.apk` below. Requires Android 8.0 or newer. See the README for the full guide to the keys.