Hey there! Sorry I'm late to the party, but I am the developer of an iPhone / iPad app called "My Tennis Stats" (and "My Tennis Stats HD" for the iPad).
It's my belief that MTS excels where Tennis Trakker falls short.
1 & 2 - we allow you to track returns, whether the returner hits a winner, forced error, or unforced error (no return)
3 & 4 - we allow you SHOW on a court where your approach shots were hit, where passing shots were hit, etc. Is a player double faulting into the net, wide, or long? Easy to tell with MTS. Where does a player serve when down break point? Again, easy to see with our court screens.
Oh, and we allow you to easily track statistics for all 4 players in a doubles match!
In all, we can track over 180+ different stats for each player with My Tennis Stats HD, with only a few simple taps on the device.
Please check out our website for more info: www.HDSoftwareTech.com
and look under "our software".