Should I do all the exercises on the bodybuilding app on iphone?

I have a BodyBuilding app on my iphone that gives recommended exercise for each muscle group. Each muscle group has 8-12 different exercises. Should I do all of them or just pick my top 3 or top 5 exercises I want to do from the list?

Depends how fit you are at present. Also, you are best to mix up the exercises on different days - stops your body getting "used" to a particular set of your favourites. Choose 3 - 5 to do today. Do a different set tomorrow. Do one part of your body one day and a different part the next day.