The most selling No1 paid app in Google Playstore is free Now.It cost was 3.99$ and it have over milli0n Users.It have Released a new version 5.0 is freely available. Swiftkey has changed the keyboard varine in Android.
Swiftkey has huge collection of themes with beautifull Colors to Use.It is smooth Simple and easy to use.It uses a advance algorithms to find the user preference,It is the huge improvement in android Stock keyboard.
So why the swiftkey app has change their product to free.Its because they are Using In-app Purchase to promote their product.So this app’s huge goal is the reach as many as it could.
Here is the Google Playstore link: https://play.google.com/store/apps/details?id=com.touchtype.swiftkey&referrer