NAVAir Approaches is our Terminal Approach Procedures viewer. With electronic copies of all the approach plates you need for your flight, you never have to worry about carrying paper plates and managing updates.
I think I have tried all of the PDA based applications and I also tried WxWorx in an earlier version using a laptop. The one I am using now is NAVAir which so far has performed extremely well. I am reluctant to get into PC based applications because of the altitude issue since I regularly fly at 12000 and above. ATC direct routing is very easy to get when you are at 14000. No one else is there.