App was easy to install. Only thing I had to do to get it working (other than to use the right password < G > ) was to enable XML-RPC under Settings, Writing to get the WordPress iPhone app to start working.
The iPhone app also makes it easy to edit an existing post without too much trouble. Biggest challenge I have had is getting the cursor to where I want it to be. That is more of a problem with the size of my finger vs. the size of the iPhone screen.
iPad version works similar to it’s iPhone counterpart. I have seen a minor but annoying problem with both clients where I have to go into edit mode for the blog profile, save it which forces it to “reverify” the blog and then I can get in.