What's the best Android app for building custom stretching routines?

Bend is a stretching and flexibility app that stands out for its robust custom routine builder, making it ideal for users who want tailored workouts. The app allows individuals to select specific exercises, set durations, and organize sequences based on their available time or focus areas, such as morning stretches or post-workout cool-downs. Features like video demonstrations and written guides help beginners learn proper form, while adjustable timers accommodate varying schedules. Users report significant flexibility improvements within weeks when following consistent routines. However, some limitations include the inability to disable automatic side-switching for certain exercises, which can interrupt flow for those preferring unilateral training. Additionally, the app's immediate push for premium upgrades upon setup has drawn criticism for aggressive sales tactics. Despite these issues, Bend's free version remains functional with ads, and the custom routine capability addresses common user needs effectively.