There is a nice feature that YouTube app provides in iPhone and Android, you can skip forward or rewind backward.
Double-tap on the RIGHT side of the playing video for moving forward.
Double-tap on the LEFT side of the playing video for moving backward
You can set the number of seconds that needs to be jumped from the settings, here is how,
- Go to your YouTube app settings
- Go to General
- tap on Double-tap to seek
- There are choices from 5 seconds to 60 seconds.
Hope this helps!