SideProjectors - Marketplace to buy and sell side projects
Hygger - Hygger - is an Agile project management tool with built-in prioritization.
Transferslot - Easily buy and sell side-projects
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
1Kprojects - Neglected side projects for less than $1000.
Validated ideas - List of 5,000 poorly executed but popular apps