I quickly checked the apps suggested by you, all of them are different. Each of them tie up the user in some way. RunKeper has probably got pre set activity types and it has only the outdoor work outs. Also requires GPS. Gympact is more of a stake and earn money app than something to track your work outs. Fitbit has also got pre set activity types. Was unable to check fitocracy but even that appears to be like these.
SweatTrack is an app just intended to make logging of your work outs as easy as possible. It is just intended to be a replacement for excel spreadsheets and (of course I am biased) can be darn quite convenient. Everything is at the hand of users. Add work outs, edit them, have templates, do whatever you want. You can even have default values set for different routines. You can have a quick look here and even try the app.
http://visceralcoder.wordpress.com/category/sweattrack/
Honestly, I have hardly seen any fitness app which give the control to user entirely. Of course such apps must be there but they are currently totally eclipsed by the heavy apps such as the ones mentioned by you.
