I have used both of these apps for different things. They are both free to use in limited capacity, or you can pay to have all features unlocked. Both contain an extensive exercise library and a way to add limited custom exercises, and a handful or custom workout routines. I like and use Strong to track my personal workouts, but Hevy is a great app and also has the benefit of allowing you to track your bodyweight and other measurements if you need to. These aren't affiliate links, I just wanted to get the information out there!