Invision - Prototyping and collaboration for design teams
InboxDollars - Earn cash for your everyday online activities.
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.
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Axure RP - The prototyping and specification software used by 87% of the Fortune 100. Beyond mockups, design interactive prototypes for business solutions, websites, and applications.
Acorn Hunt - Acorn Hunt is an app that comes up with different ways to provide you entertainment and win real money.