Personal training app?

NaomisGonnaWin

Can any of you recommend a good personal training app for strength training?

I'm looking for something that can be used both when I go to the gym - to guide me through workouts - and when I work out at home, with just body weight and a few dumbbells.
I'm also looking for something that can take my current strength level into account (i.e. if an app tells me right off the bat to do 10 pull-ups, well, that just ain't gonna happen).
Another plus would be if I could have it focus on different body parts on different days - ie a legs day, an arms day, a core day, etc.

I've been trying out GAIN Fitness lately, but I'm not too thrilled with it. It's pretty inflexible.

So... suggestions?