OpenCalc v1.0.0 — First Stable Release 🎉

🎉 OpenCalc v1.0.0 — First Stable Release

The first installable Android APK is here! After weeks of development and a one-day delay to finalise the build, OpenCalc v1.0.0 is ready. Thank you for your patience. ❤️

---

📦 Download

File	Size	Description
OpenCalc-v1.0.0.apk	~25 MB	Signed Android APK (Android 7.0+)
OpenCalc-v1.0.0.apk.sha256	65 B	SHA256 checksum for integrity

Install on Android

1. Download OpenCalc-v1.0.0.apk to your Android device
2. Open Settings → Security (or Apps → Special access → Install unknown apps on newer Android)
3. Enable "Install unknown apps" for your browser
4. Tap the downloaded APK and select Install
5. Open OpenCalc from your app drawer 🎉

⚠️ Verify the download (optional):

sha256sum OpenCalc-v1.0.0.apk
# Compare with OpenCalc-v1.0.0.apk.sha256

Alternative: Install as PWA (no APK needed)

Don't want to sideload? OpenCalc is also installable as a Progressive Web App:

1. Visit https://open-calc-7.netlify.app/ in Chrome (mobile or desktop)
2. Tap the Install icon in the address bar
3. OpenCalc appears in your app drawer / launcher

---

🆕 What's new in v1.0.0

Headline

• 📱 First Android APK — signed, installable on any Android 7.0+ device
• 🏷️ Semantic versioning kicks off here (v1.0.0)
• 🤖 GitHub Actions auto-build the APK on every v* tag push

Fixes from v0.0.9

• 🫥 History button overlap FIXED — top bar restructured to a 2-row layout. History button now has a live count badge.
• 🎯 D-pad added (↑ ↓ ← →) — compact 4-directional navigation cluster in the display. Permanently visible, even when input is empty.
• 👀 Always-visible caret — blinking caret shown at all times (even when LaTeX renders) so you always know where input will land.
• 📜 History access from Settings — new History section at the top of Settings with current count + favorites count.
• 🛡️ Privacy & Permissions section in Settings — shows what data is stored, what permissions are requested, and links to the full privacy policy.
• 📅 Launch date moved from July 1 → July 2 — to finalise the APK wrapper, signing, and QA.

---

✨ Features

OpenCalc ships with three calculators in one elegant app:

🧮 Normal Mode

Full arithmetic, memory (MC/MR/M+/M−), undo/redo, percent, power, parentheses, keyboard shortcuts.

🔬 Scientific Mode

• Trig: sin, cos, tan, cot, sec, csc + all inverses (sin⁻¹, cos⁻¹, tan⁻¹, etc.)
• Logs: ln, log, eˣ, 10ˣ
• Powers: x², x³, xʸ, √, ∛, ʸ√x, 1/x, n!
• Combinatorics: nPr, nCr
• Misc: |x|, mod, rand, floor, π, e, τ, φ
• Fraction templates: a/b and compound a/b/c with caret positioning
• DEG / RAD toggle
• Caret navigation: ← → arrow keys

🔄 Unit Converter

108 units across 13 categories:

• 📏 Length (13 units)
• ⚖️ Mass (11)
• 🌡️ Temperature (4)
• 🟧 Area (10)
• 🧊 Volume (14)
• ⏱️ Time (12)
• 💨 Speed (7)
• 💾 Digital storage (10)
• ⚡ Energy (9)
• 🔌 Power (7)
• 🎈 Pressure (8)
• 📐 Angle (6)
• 📻 Frequency (6)

Features searchable picker, swap button, copy & share.

🧠 Step-by-Step Solver

Press = then Steps to see:

1. The expression in mathematical notation
2. Algebraic simplification
3. Rational form (where applicable)
4. Numeric evaluation with angle-unit context

🌈 Live LaTeX Rendering

Every expression is typeset in real time using KaTeX — including incomplete ones. The fraction template shows □/□ until you fill it in.

📜 Persistent History

• Searchable, favorite-able, copy & share
• Stored locally (offline-first)
• Cloud sync coming in v1.1 (opt-in)

🎨 Premium Material 3 Design

• Custom emerald + amber palette
• Spring-animated segmented toggles
• Fully rounded keys with distinct backgrounds and rings
• Light/Dark themes (follows system preference)
• Smooth 60fps animations

♿ Accessibility

• ARIA roles, semantic HTML
• Keyboard navigation
• Screen-reader labels
• Adjustable haptic feedback intensity

⚙️ Customisation

• Orientation: Auto / Portrait / Landscape
• Decimal places: Auto / 2 / 4 / 6 / 8
• Angle unit: DEG / RAD
• Haptics: Off / Light / Medium / Strong
• Theme: Light / Dark

---

🛡️ Privacy

OpenCalc is privacy-friendly by design:

• ✅ No data collection
• ✅ No analytics
• ✅ No trackers
• ✅ No backend server
• ✅ All data stored locally on device
• ✅ Only 2 permissions: VIBRATE (for haptics) + INTERNET (required by WebView)

Full privacy policy: PRIVACY.md

---

🛠️ Tech Stack

Layer	Technology
Framework	Next.js 16 (App Router)
Language	TypeScript 5
UI	shadcn/ui + custom Material 3 keys
Styling	Tailwind CSS 4 + custom OKLCH tokens
Animation	Framer Motion 12
State	Zustand 5 (persisted)
Math	mathjs
LaTeX	KaTeX
Native shell	Capacitor 8
Database	Prisma + SQLite (local)
Auth	TBD — Supabase planned for v1.1
Hosting	Netlify (live preview)

---

📸 Screenshots

See the /public/screenshots/ folder in the repo for full-resolution images:

1. Normal mode (light, empty state with D-pad)
2. Normal calculation result
3. Normal mode (dark, empty)
4. Normal calculation (dark)
5. Scientific mode (dark)
6. Scientific mode (light)
7. Unit converter (light, empty)
8. Unit converter — 1000 m → 1 km
9. History panel with search + favorites
10. Settings panel
11. Settings → Privacy & Permissions section
12. Step-by-step solver drawer

---

📋 Installation requirements

• Android: 7.0 (API 24) or higher — covers ~99% of active devices
• Storage: ~25 MB for the APK
• Permissions: VIBRATE (optional, default on), INTERNET (auto-granted by WebView)
• No Google account required
• No internet required after install

---

🗺️ What's next — v1.1+

• 🔐 User authentication — Email, Google, Anonymous Guest (Supabase)
• ☁️ Cloud history sync — optional, opt-in
• 📊 Graphing calculator — plot functions
• 💱 Currency converter — live exchange rates
• 🤖 AI explanation of solutions — natural-language walkthroughs
• 🎙️ Voice input — speak your calculation
• ✍️ Handwriting recognition — write math by hand
• 📷 Equation scanner — point your camera at a problem
• ⌚ Wear OS support — quick calcs on your watch
• 🌍 Internationalization — multi-language UI
• 🧪 Unit + integration tests — full coverage
• 🏠 Home screen widgets — Quick Calculator, Recent Calculation, Scientific Shortcut

---

🤝 Contributing

OpenCalc is open source (MIT License). We welcome contributions!

• 🐛 Report a bug
• 💡 Suggest a feature
• 🔧 Read CONTRIBUTING.md
• ⭐ Star the repo

---

📄 License

MIT — see LICENSE.

---

🙏 Acknowledgements

• mathjs — the math engine
• KaTeX — LaTeX rendering
• Next.js — the framework
• shadcn/ui — UI components
• Framer Motion — animations
• Capacitor — native wrapper
• Material Design 3 — design inspiration
• Netlify — live preview hosting
• Every contributor and tester ❤️

---

Built with ❤️ by huzaifaa-dev-vibe and contributors.

⭐ Star · 🐛 Report bug · 💡 Feature request · 🌐 Live preview · 📖 Docs