Convert mp4 to webm

https://thethemefoundry.com/blog/convert-mp4-to-webm/

Play mp3 on Target's Device

http://ubuntu-for-humans.blogspot.co.id/2010/03/how-to-play-mp3s-from-terminal-on.html

Fixing Kali Linux No Sound

https://forums.kali.org/showthread.php?30815-No-sound-how-to-start-pulseaudio-on-startup

Add ppa on nethunter

http://askubuntu.com/questions/38021/how-to-add-a-ppa-on-a-server