GoodBarber - GoodBarber is a mobile app creation platform.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Bizness Apps - Create your own app or become a reseller and build apps for others
BuildFire - BuildFire is the easiest way for small businesses to build a mobile app in a matter of minutes for iOS and Android.
Dropsource - Mobile development platform for building native iOS & Android apps
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.