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.
Intervally - Interval Timer - Sport & Health
MyFitnessPal - Track the number of calories that you consume each day with MyFitnessPal. The app also lets you create a diet and track the exercise that you complete each day whether it's walking, running or some other type of program.
HIIT Interval Buddy - Let Interval Buddy help you with your high intensity interval training - a popular method of high-impact cardio fitness training that reduces time spent in the gym and makes cardio training less of a bore.
Runtastic - Runtastic offers a series of fitness apps that can be used to track your running, walking, hiking, and cycling, as well as many other fitness routines. Read more about Runtastic.
HIIT (Watch) - A very simple interval timer engineered for Apple Watch