Invision - Prototyping and collaboration for design teams
Design Business - Database of design agencies, news, and useful materials.
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.
Brace - Access to the best developers for $0
UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Conceptzilla - Get competitive design for a fraction of the industry cost