Visily - The easiest and most powerful wireframe software for agile teams.
Fancybox - fancyapps.com - Fancy App Store
Learn SpriteKit by Design+Code - Make a platformer iPhone game from scratch in Swift 4.
PhotoSwipe - JavaScript gallery, no dependencies.
Bootsketch - Ship products instead of renaming layer groups
Magnific Popup - The greater part of Lightbox modules will completely preload a picture before showing it.