Typ-O HD - $14.99

http://itunes.apple.com/us/app/typ-o-hd-writing-is-for-everybody/id372971659?mt=8

Compatible with iPhone, iPad, and iPod touch. Requires iOS 7.0 or later. This app is optimized for iPhone 5.

This app uses word prediction and has a sophisticated spelling error model to help you focus on the content of your writing. Typ-O is able to identify the most common spelling mistakes and will often suggest words.

See more about this application. [1]