Sketch - Professional digital design for Mac.
Bizness Apps - Create your own app or become a reseller and build apps for others
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Siberian CMS - Siberian is an Open-Source and Free App Maker. Unlimited Push Notifications. Unlimited features. Fully Customizable. Download it and build your own app now!
Affinity Designer - Professional creative software, exclusively for Mac.
Dropsource - Mobile development platform for building native iOS & Android apps