UberClassifieds is a good idea, it combines Backpage, Cragslist, Kijiji, Oodle, Ebay, and Used Everywhere, into on app. The idea is great but the app isn't so great.
The problem I have with the app is that you have to search for an item. While search is an important to have I like to browse the websites. Even when I'm looking for something I browse because a lot of people don't list their items in a way that works well with search. I just tried it out searching for cell phones, yes I know it's a little wide open, my responses were a diaper bag, 2010 Ford Tarsus, Horse Boarding, 2010 Dodge Charger and several other unrelated items. In fact out of the 20 or so items listed I think there were 3 items that were cell phones.
Hopefully they see this and put out an update that would improve their search and give the ability to browse but until they do I could not recommend this app to anyone.
$1.99 in App Store