I have been using Trello daily for my own project management tracking. Saving the website as a 'webapp' on the iPad was OK... you could get by.
However many things were buggy - if you had a card with many records scrolling sometimes scrolled the background faded page rather than the card itself.
Entering text into comment fields was OK until you hit backspace, at which point the page scrolled somewhere else and you couldn't see the text anymore.
I love the app. Now I just need the ability to move cards between boards.