Build a lightweight, offline-first flashcard product centered on an explicit "Study Entire Deck" action, with no algorithmic limits. It would support text, images, and multiple-choice cards; local backup and export; and optional spaced repetition that remains disabled unless selected. Sell the core product through a transparent one-time purchase, with an optional paid cross-device backup service rather than advertising or essential-feature subscriptions.

Multiple established learning products are adding AI features, advertising, and subscription restrictions while users continue asking for speed, reliability, offline access, and direct control. That creates room for a deliberately narrow product optimized for exam cramming and low-resource devices.