Get this app.
Seriously. It rocks. I have a ton of apps and this is one of them that I use all the time. Today, I was in desperate need of a shower...like I was too dirty to be out in public, even at the gym. So, I enjoyed the 5 foot by 5 foot open space in my office and sweated up a storm while watching the Today Show.
Warning...I work out all the time. But I can only do 45 min on beginner. It's tough. But fantastic. All you need is your phone, hand weights and a medicine ball.
(I think it might be free too!)