Chupamobile is a pretty cool resource. I've made some decent cash with it. Here's an idea.... Sell shovels to gold miners. Have a developer from Odesk make a few simple games from scratch. Then go and list the source codes on chupamobile and sellmyapp.com for $99-$150 a pop per license. 2-3 sales a day turns into a pretty sweet passive business. Almost no work involved.