Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Fuse - Fuse is a UX tool suite for mobile app designers and developers.
Sencha Touch - The leading mobile web app framework based on HTML5 for amazing mobile apps.
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!
App Press - App Press provides tools to create and publish apps for iOS and Android.
GoodBarber - GoodBarber is a mobile app creation platform.