Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Typorama - Typorama: Text on Photo Editor is a Typography Art and Poster Maker application created and published by Apperto Ltd.
BuildFire - BuildFire is the easiest way for small businesses to build a mobile app in a matter of minutes for iOS and Android.
TypeSlab - Simple, shareable typographic posters
MIT App Inventor - App Inventor is a cloud-based tool, which means you can create apps for phones or tablets right in your web browser.
Bold - Ultra-fast anonymous publishing platform.