Calculator M3
- AI Math Solver: the Stop button stays on screen while solving in landscape
Unlike other calculators, this app doesn't phone home. No usage tracking, no telemetry, no ad frameworks buried in the code. It does math — and an optional, fully on-device AI math solver — and nothing else.
✓ Full expression evaluation
✓ Live result preview
✓ Scientific functions
✓ Calculation history
✓ Material 3 dynamic theming
✓ Works offline (with an optional on-device AI math solver)
🔢 FULL EXPRESSION EVALUATION
Type complete mathematical expressions with proper operator precedence (PEMDAS) and parentheses up to 20 levels deep. See the result update in real-time as you type.
- Full PEMDAS operator precedence
- Parentheses with 20 levels of nesting
- Live result preview as you type
- Tap anywhere in the expression to edit
- High-precision BigDecimal arithmetic
- Engineering notation for large numbers
🔬 SCIENTIFIC FUNCTIONS
- Square root (√)
- Pi (π) constant
- Power (^) exponentiation
- Factorial (!) for values 0-99
- Percent (%) with consumer-style support
- Implicit multiplication (2π, 3√2, etc.)
📜 CALCULATION HISTORY
- Stores up to 100 recent calculations
- Persists across app restarts
- Tap entries to reload them
- Clear history when needed
📷 AI MATH SOLVER (OPTIONAL, EXPERIMENTAL)
An experimental extra for higher-RAM devices: photograph a handwritten math expression and let an on-device AI model read and solve it — entirely on your device, with nothing sent to any server.
➡️ HOW TO TURN IT ON: the AI features are hidden until you unlock them. In the calculator, tap the "AC" (all-clear) button 7 times in quick succession — a countdown guides the final taps. A camera icon then appears in the top-left corner, and the unlock is remembered.
- Needs a 6 GB+ device and a one-time vision-model download (2.6–4.9 GB)
- Take a photo with your system camera, or pick one from your gallery
- Choose from several open vision models (Gemma 4, Gemma 3n)
- Models run fully on-device, GPU-accelerated where supported
- The solution is shown with cleanly formatted math — fractions, roots, and exponents
- Internet is used only once, to download the model you choose
- No photo, calculation, or usage data ever leaves your device
🎨 MATERIAL 3 DESIGN
- Material You dynamic colors (Android 12+)
- Automatic light and dark mode
- Smooth button press animations
- Haptic feedback
- Adaptive layout for portrait, landscape, and foldable devices
- Auto-sizing display for long expressions
🛡️ PRIVACY & OPEN SOURCE
- 100% open source (GPL v3)
- No tracking, analytics, or ads
- No data collection of any kind
- The calculator itself needs no network at all
- Internet is used only if you opt in to download an AI model — never to send your data
- Your calculations and photos stay on your device, period
📱 WORKS ON ALL DEVICES
- Phones in portrait and landscape
- Foldable devices (Pixel Fold, Galaxy Z Fold)
- Tablets
- Responsive button sizing and layout
- Author: Gergely Vagujhelyi
- License: GNU General Public License v3.0 only
- Issue Tracker
- Source Code
- Build Metadata
- Reproducibility Status
Versions
Although APK downloads are available below to give you the choice, you should be aware that by installing that way you will not receive update notifications and it's a less secure way to download. We recommend that you install the F-Droid client and use that.
Download F-Droid-
arm64-v8aThis version requires Android 8.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Download APK 12 MiB PGP Signature | Build Log
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arm64-v8aThis version requires Android 8.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Download APK 12 MiB PGP Signature | Build Log
-
arm64-v8aarmeabi-v7ax86x86_64This version requires Android 8.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Download APK 1.3 MiB PGP Signature | Build Log
- Hidden until you reveal it: tap AC 7 times quickly
- Runs offline on Google LiteRT-LM, GPU-accelerated
- Snap a photo or pick one from your gallery
- Several Gemma vision models; background downloads resume if interrupted and can be stopped
- Gated models unlock with a one-tap Hugging Face sign-in
Your photos never leave your device — internet only downloads the model you pick.