- Added 700+ focused backflow certification practice questions
- Added detailed explanations and study references
- Added 24 flashcards and 5 study guide topics
- Added timed mock exam mode
- Added progress tracking, bookmarks, and weak-area review
- Added interactive tools for assembly selection, field testing, pressure readings, documentation, and troubleshooting
- Added Pro access with monthly, annual, and lifetime options
- Improved purchase, restore, and unlock flow with Google Play Billing