This utility app provides a Reverse Polish Notation (RPN) calculator. Users can extend its functionality by programming custom functions and equations using JavaScript.
ThetaCalc by Felix Stehli






12+ iOS apps & games curated and reviewed
Out of 12+ felix stehli apps and games on iOS, 12 are free and the rest sit in the paid tier. This page sorts them so you can compare both sides before you commit.
| # | App | Price | Rating | Ads | In-App Purchases | Updated | |
|---|---|---|---|---|---|---|---|
| 1 | Free | 4.3★ (4) | No | No | May 2026 | ||
| 2 | Free | 5.0★ (3) | No | No | Oct 2026 | ||
| 3 | Free | — | No | No | May 2026 | ||
| 4 | Free | 5.0★ (1) | No | No | Oct 2026 | ||
| 5 | Free | 1.8★ (23) | No | Yes | Oct 2026 | ||
| 6 | Free | 5.0★ (1) | No | Yes | Oct 2026 | ||
| 7 | Free | — | No | Yes | Sep 2026 | ||
| 8 | Free | — | No | Yes | Oct 2026 |






This utility app provides a Reverse Polish Notation (RPN) calculator. Users can extend its functionality by programming custom functions and equations using JavaScript.






This app solves a variety of tile-based puzzles, including pentominoes, tetrominoes, and more. It can handle puzzles of any shape and any combination of these pieces.



