To develop an AI personal trainer app like Aaptiv, begin by outlining the core fitness features your app will offer—AI workout suggestions, audio-based sessions, and personalized routines. Advanced AI models should study user preferences, body metrics, and weekly performance to adjust training plans automatically. Include voice-assisted coaching, progress analytics, and motivational reminders. Build a strong UI that makes selecting and following workouts simple. Incorporate wearable data to increase training precision. A scalable backend helps manage large content libraries and AI algorithms. Testing and user feedback ensure better accuracy and user satisfaction. With these elements, you can create an intelligent fitness app similar to Aaptiv.