I use iswifter sometimes, and Splashtop when I get home. But a buddy I play squash with recommended skyfire. The reviews on the app store for it are terrible, though.
There is also Puffin, but there may also be another option I don’t know of. The posters on the iPad forums I frequent are morons, so I thought I’d ask the folks on here! which one of these cloud servers runs the smoothest? 
Thanks!
P.S., For the sake of limiting this thread, I only want to consider standalone apps. Not ones that connect to my home PC.