I use this app when I am on the road, and the hotel gym is not very good. It actually can get you breathing pretty hard. I do the workout 2-3 times, like sets, and it gets me feeling like Ive worked out for the day. I added the voice option, which helps so I dont have to run over to my phone to see the next exercise. Simple, but it works.
SilvaLining about 7 Minute High Fitness Work Out