wger - FLOSS workout, fitness and weight manager/tracker written with Django
Strong.app - Strenght training logger.
Strongify - Strongify is the easiest workout tracker app. Enter the number of reps and the weight you lifted in just a few taps. Create any exercise that you want and track your progress over time.
The Fit Tutor - The Fit Tutor is a membership community dedicated to efficient and effective workouts for all...
JEFIT - Jefit is the #1 popular gym workout app for Android and iOS. Jefit allows you to manage your training routine and keep track of your workout progress easily.
Liftosaur - Free weightlifting tracking app where you can code