Syntactic vs Codex Meter

Syntactic is a complete Rust learning environment that runs entirely on your device — a real Rust compiler in your pocket. WRITE AND RUN REAL RUST Write Rust in a fast editor with syntax highlighting, inline errors, and code completion, then compile and run it on-device. No account, no server round-trip, no internet required — the actual Rust compiler runs on your iPhone and iPad. LEARN FROM THE RUST BOOK The complete Rust Programming Language book is built in, formatted for comfortable reading, with runnable examples one tap from the editor. Check your understanding with built-in quizzes as you go. PRACTICE WITH CHALLENGES Sharpen your skills with 66 hands-on coding challenges across three difficulty tiers. Write your solution, tap Submit, and an on-device test suite grades it instantly — with the failing case and your own debug output right there when you need them. EXPLAIN ERRORS WITH ON-DEVICE AI (OPTIONAL) Stuck on a compiler error? An optional on-device AI can explain it in plain language, grounded in your own code — downloaded only if you choose, and running fully offline. EVERYTHING ON-DEVICE Your code never leaves your device. There is no sign-in and no tracking. Compiling, running, reading, and practicing all work completely offline, anywhere. Syntactic is an independent, unofficial app. It is not affiliated with or endorsed by the Rust Foundation.

Codex Meter puts your Codex allowance where it is easy to check—on your iPhone, iPad, and Home Screen. Sign in with your existing OpenAI account to see your current five-hour and weekly usage windows, upcoming reset times, plan status, and earned reset credits. Clear visual meters make the important numbers easy to understand without repeatedly opening a browser. FEATURES Five-hour and weekly Codex allowance meters Locally updating reset countdowns Earned reset-credit inventory and expiry information Confirmation before reset-credit redemption Home Screen and accessory widgets Optional refill, credit increase, and credit expiry notifications Background refresh and offline display of the latest successful update Offline demo mode for exploring the interface without signing in PRIVATE BY DESIGN Codex Meter has no analytics, advertising, developer-operated account system, or relay server. Credentials stay in Apple Keychain, and authenticated requests go directly from your device to OpenAI. Codex Meter is an independent, unofficial client and is not affiliated with or endorsed by OpenAI. ChatGPT and Codex are trademarks of their respective owners.