Personal Database Builder: Ideal application for recording and storing videos, web links, and text by topic and subtopic to aid learning. Especially good for physical activities like martial arts, dancing, and playing musical instruments, which defy words alone. Content can be shared between users as zip files that populate the receiver's database.
Jiu-Jitsu: https://youtu.be/-Y2JRiSeBZI
Bachata: https://youtu.be/qm90TXw8qUw