I also want to add, when making a video recording of how to use an app, recording the visual mouse movements on a tablet using a Bluetooth mouse, I sometimes also make a separate audio recording at the same time using my iPhone with the VoiceMemo app. When I'm done with the video screen recording I merge the video with the audio recording from my other device, to include voice instructions, notes, and walkthrough information about the app. Merging the two assets together will result in one fine video recording of how to use the app you're documenting.
A note about the above process. Sometimes the audio recording and the video recording will not be in synch with each other. I find I may need to cut out one second of video per minute to keep a longer recording from slipping too much out of sync in the final piece. Results may vary for you, so this is just an observation to be aware of with your own recording. Good luck!