Microsoft has begun inviting people who registered to test its Word Flow keyboard to download the app from the iTunes App Store.
Microsoft had been testing the alternate keyboard in a closed beta, but started accepting signups earlier this month.
One the iPhone, Word Flow will support custom backgrounds, one-handed typing, and swiping gestures to spell words.
The keyboard was developed by Microsoft’s Garage unit, which heads up projects for Android and iOS. Word Flow for the iPhone only supports English at launch.
It is free to download and use.