Tasker - Tasker is an application for Android which performs Tasks (sets of Actions) based on Contexts...
iFit – Workouts at Home - iFit – Workouts at Home app allows users to access an extensive collection of thousands of home workouts with advice and motivation from world-class fitness trainers.
AutomateIt - Automate Your Android!
Strava - The #1 app for runners and cyclists
LIama - LIama is a Location-Aware Mobile app that determines your location and helps you do lots of other stuff with ease.
BitGym - Virtual Cardio Tours. No heart rate sensor of special hardware required.