I recommend the workouts as they are both challenging (you can always push yourself to go harder) and high energy. The voiceover prompts are also nice as they keep you on pace and alert as to whats coming up next. That said...
The app, however, lacks some basic needs (especially for a $3 paid app).
1. the auto reminder that sends a push notification to remind you to workout has not worked once since I purchased it.
2. The customer support has yet to respond to any of my three emails about the push notification issue.
3. The app should allow me to record more than my bodyweight (i.e., my heart rate before and after workout would be a great addition).
4. The app should allow me to record my reps at the end of the 7 minutes. This way I can track my progress
So, if you want an app thats good for a quick workout, bad for tech-support, and ok on features this is it.