RustChap vs Math Vale

RustChap teaches the Rust programming language the way Euclidea teaches geometry: through small puzzles with exact answers. You do not type code on a phone keyboard. You tap tokens, reorder statements, and pick the best implementation. Every possible answer was compiled ahead of time with the real Rust compiler, so every verdict - compile error, test failure, or optimal solution - is the compiler's truth, not a quiz author's opinion. - 15 decks following one arc: ownership, borrowing, lifetimes, slices, Option and Result, pattern matching, iterators, closures, traits, generics, smart pointers, interior mutability, API design, async, and unsafe. - More than 60 puzzles, each teaching exactly one instinct. Match the star budget - like 0 clones in 2 edits - to earn the Optimal rank. - 20 short lectures in plain English. Every deck opens with one. - An AI tutor that knows the puzzle you are looking at. It runs on your device by default; nothing leaves your phone. Optionally use your own OpenRouter key for a cloud model. - Fully offline. No account, no ads, no tracking, no server. Built for experienced programmers who want Rust to feel like instinct. From Uncle Code, author of Crawl4AI. Built while skilling up for a Rust rewrite, inspired by many playthroughs of Euclidea. The full source is public at github.com/unclecode/rustchap - contributions welcome. RustChap is an independent educational app. It is not affiliated with or endorsed by the Rust Foundation. Ferris artwork by Karen Rustad Tolva (CC0).

Math Vale is a role-playing game where the world runs on mathematics. Every kingdom is a branch of it, every Keeper guarding a gate is a set of real problems, and the only way forward is to understand the idea — there is nothing to grind and nothing to rush. • 141 skills across eleven kingdoms, from counting and fractions to trigonometry, calculus and linear algebra • Lessons that explain, hints that nudge without giving the answer away, and a Journal that keeps every mistake so you can fix it later • Problems that adapt to what you know, and reviews that come back when a skill starts to fade • A homestead to build, quests, dragons and hidden caves of competition problems • Play alongside classmates and family, spar with a friend, or defend a castle together Four kingdoms are free for ever — counting, number sense, fractions and algebra — with no limit on how much you play. The other seven, geometry through calculus and linear algebra, open with a subscription or a one-off unlock, and a free fortnight begins the first time you reach them. Nothing inside the game is ever for sale: no coins, no lives, no hints. Built for children, so it asks for very little: a username, a display name and a password — no email, no phone number, no date of birth. No adverts, no analytics, no tracking. Subscription and purchase terms • Math Vale, a year: an auto-renewing annual subscription that opens every kingdom. • Math Vale, for good: a one-off purchase that opens every kingdom and never renews. Payment is charged to your Apple Account when you confirm the purchase. The subscription renews automatically at the same price unless it is cancelled at least 24 hours before the end of the current year. You can manage or cancel it in your Apple Account settings at any time. Terms of Use: https://mathvale.com/terms Apple's Standard License Agreement (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://mathvale.com/privacy