Show HN: Lathoa, a math app for kids where the AI is wrong on purpose

Lathoa is a math app for 10-14 year olds that trains critical thinking by having an AI companion deliberately make a wrong step in multi-step problems. Each challenge shows a step‑by‑step solution with exactly one incorrect move; the child reads the "case," taps the wrong step, types a short explanation of the error, and earns detective ranks (Rookie → Sherlock). Problems are tiered by difficulty (Obvious, Sneaky, Expert), aligned to Common Core 4-8 topics (arithmetic, fractions, ratios, pre‑algebra, early geometry), and include features like a confidence meter on the AI, emotional feedback when kids catch or miss mistakes, replayable case files, and shareable evidence of past catches.

The core argument is that spotting flawed reasoning is a more important skill than getting correct answers in an age of ubiquitous AI. Lathoa combines generated content with human verification so intentionally wrong steps are reliable and safe, avoids ads and data harvesting, and is COPPA‑respecting. A free tier offers three cases per day; paid tiers add unlimited cases, parent dashboards, progress digests, misconception flags, and family or school licensing. The product runs in any browser and on mobile, offers a seven‑day parent trial with no card required, and promotes hands‑on error‑detection as AI literacy for kids.