FORTE

Forte borrows the one thing games get right about progress — you can see it — and points it at real practice. Skills live in an auto-laid-out tree (dagre for layout, d3-zoom for pan and pinch) and unlock on concrete, self-assessable criteria rather than vague vibes: "clean F barre — all six strings ring", not "get better at chords". Unlocked skills feed six stats — strength, endurance, mobility, coordination, intellect, awareness — mapped onto a character figure whose body regions fill and glow as you go. A one-tap session timer logs practice without nagging you about streaks.

It runs entirely on the device: all state lives in IndexedDB through Dexie, with JSON export/import for backup, so there's no backend, no account, and no network dependency — installable on iOS and fully usable offline. Trees are plain JSON validated against a schema, so anyone can author their own. The domain layer (tree parsing, unlock rules) is kept pure and unit-tested, separate from the React and storage layers. A personal tool, built in the open.