For Avaz version 6.6.5 and above:
To locate the current version of Avaz that is running on your device, tap the Menu button, located at the top right of the screen). Once you’re in the Menu, you’ll find the version number displayed at the bottom right corner.
For lower versions of Avaz:
You will find the Avaz version number displayed at the bottom of the Settings menu when you scroll down to the end.