A full version program for Android, by Webrich Software.

Grammar: Change of Voice Lite is an Android app that helps you master the change of voice from one grammatical form to another. It contains over 46 pages of lessons with several examples that explain how to change the voice from one grammatical form to another without changing the meaning. 

This app is designed to be used in a similar way to English classes, in order to learn the grammar rules, study the examples, and test their understanding by taking a quiz. It can help you improve your understanding of Active and Passive Voice and make use of various expressions in writing English. Custom timer settings can assist you to improve response times under exam time constraints.