SmileOnMyMac, LLC has TextExpander 3 + Custom Keyboard (iTunes Link) for the iPhone, iPod Touch, and iPad in the iTunes App Store for 99-cents (regularly $4.99) for a limited time.

Type faster on your iPhone®, iPad, or iPod touch in any App using the TextExpander keyboard. The keyboard enables custom abbreviations to expand into long snippets of text, such as addresses, URLs, email signatures, and form letters. You can even insert today’s date automatically with the default abbreviation “ddate”!