What's a solid Android app for getting in a quick workout at home when I'm short on time and equipment?

Okay, so I've been using Home Workout - No Equipment, and it's been a total lifesaver for those days when I can't make it to the gym. As a fitness instructor, I need to stay on top of my game, and this app lets me do just that. What I love is that it gets you moving without being preachy. The variety of workouts is awesome; I can target specific muscle groups or go for a full-body blast. Plus, it tracks my heart rate zones accurately, which is crucial for optimizing my effort. It's perfect between sets when I'm designing programs for my clients, too. I love that it reminds me to hydrate, which is key for solid performance. I haven't tried syncing it with other apps yet, but I'm sure it's compatible with the big players. Honestly, it's been a solid addition to my fitness toolkit.