First of all, unbeknownst to me, the Nike Training Club is primarily geared towards women. Do a search for Nike Training Club and you'll get a ton of links to Nike Women sites. Exercise is exercise though, and even though all the pictures and examples are of women, the fast paced exercises in the program will certainly get you in very good shape.
The app is primarily based by needs, so the training can be used for people of all different experience levels and all different body types. The four areas are "Get Lean," "Get Toned," "Get Strong," and "Get Focused," which has a range of focused workouts for different body types. Inside of each section there are subsections that contain different workouts, depending on what level of training you are at. If you are a beginner looking to get strong you can bust out the "Magnum" workout that contains 45 minutes of rapid workouts, but if you are die-hard crazy, you can take on the 45 min "Adrenaline Hit" that will surely leave you as a sweaty mess.
Each exercise in the app is accompanied by a set of example pictures that walk you through the movements, as well as a video showing the perfect motion of the exercise in high res glory. In fact, everything about the app, from the powerful black and white with bold letters theme to the high quality examples is top notch. If you're looking for a nice looking app with no weird quirks, you're looking in the right place.
Once you've conquered some of the workouts, you can start working towards the Nike Training Club goals, which are primarily symbolic but at times give you additional workouts and celebrity training guides. Your progress is all tracked by time though, so you'll only get as much out of the app as you put in. Just because the app thinks you're a "Champion" after 660 minutes of working out doesn't mean that you actually did every rep, every time. Stick with the app though and good things are sure to happen.
Note: You will need a small/medium sized yoga ball and some adequate weight dumbbells for some of the workouts. Just an FYI.