What is the most effective way to record a videogame walkthrough directly on the BlackBerry Q10?

I want to record a video game walkthough featuring simultaneous verbal narration for the Android game "Pixel Dungeon" as played on my BlackBerry Q10.

I would also prefer to record the video and also both the spoken- and app-originated audio directly on the device if possible.

What is the most time and money cost-effective way of doing this? Thank you in advance for your assistance!

Most effective way would be to use an external recorder which allows visibility of gestures and keystrokes.

There was an app on BBW which reportedly recorded video screen shots but I cant recall name off hand and can't vouch for its reliability....will try to do some digging and if I come across it will post link.