Invision - Prototyping and collaboration for design teams
iZap - piZap Photo Editor is fun and easy to learn online photo editor & collage maker. Tons of effects, fonts, stickers, collage layouts, borders, frames, and editing tools.
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.
Bazaart - Create. Discover. Love. Social photo collage editor
UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Designify - Turn any photo into awesome, automatically