Coming next
Word Search
A classic word search app with categories, unlocks, and short sessions. It is still in development.
Independent app studio
Small apps that respect short, quiet moments.
Sunstone Apps builds mobile puzzles and everyday tools for people who want to open an app, do one thing, and come back later without friction.
About the studio
Independent studio for mobile puzzles and useful apps.
Sunstone Apps is intentionally small. Each app has to earn its place: it should start quickly, save progress clearly, and avoid turning a simple break into setup work. Daily Sudoku covers offline number puzzles. Word Search brings classic hidden-word play next.
Apps from the studio
Recent posts
Notes from the workbench
Practical notes from building, testing, publishing, and operating small apps.
React Native Skia
The rounded border that pushed every Sudoku digit off-center
A border on an overflow-hidden container silently shifted our Skia board and un-centered every digit. Here is how screenshots, not eyeballs, found the real cause in a React Native game.
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React Native tooling
Why __DEV__ is false in release builds, and how we gated dev tools by config instead
A developer shortcut hidden behind __DEV__ disappeared exactly when we needed it in a release build. Here is why that happens in React Native and how we moved the gate to runtime config.
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Design systems
Design tokens as one source of truth: giving a Sudoku app a real art direction
How we gave a template-looking Sudoku a bold art direction by changing the theme tokens first, sharing them with our website, and staying inside a low-end performance budget.
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React Native Haptics
Adding Expo haptics to a React Native game without making vibration a sound setting
How Daily Sudoku added a persisted vibration toggle, reused gameplay feedback events, and kept Web bundling safe while using expo-haptics on native.
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Built by Jonathan Reis
A small studio run by the person shipping the software.
Sunstone Apps is led by Jonathan Reis, a senior tech lead and software developer from Rio de Janeiro. The same hands-on work behind mobile apps, cloud infrastructure, DevOps, SRE, and release reliability shows up here in smaller products with tighter feedback loops.