I use PokerJournal. You can import your data to Excel, or whatever you like.
Save for one problem, which has been solved, I've been very happy with it. I think it's far superior to just using Excel. It will let you collect data much more accurately with far less effort.
After trying a bunch of apps, I turned to numbers (iPhone) and customized it just like I want. Numbers/excel is the way to go if you want the flexibility down the line.