If you're looking for a way to remotely control a Mac (i.e. in an office with a bunch of Macs you administer or from your couch because you want to turn on iTunes) you need to use a VNC1 program.
Screens VNC is what I'd buy if I had it to do all over again. And both their Mac and iOS apps are 50% off right now. Screens VNC for Mac is $14.99 and Screens VNC for iPhone and iPad is $9.99 right now during their sale.
With iCloud syncing of all your bookmarked computers it would make it simple to log in and update, fix or check on any of your Macs, Windows or Linux PCs.
Check out iMore's review of Screens for iOS below to see how it works.
Direct link to video