Very useful app.

Use this app all the time.
Even turned a few on to it to get themselves so they would quit bugging ME to tie things for them.
Awesome app.
Only suggestion I would make is pertaining to being able to differentiate between which end of rope is on top, or below when trying to tie knots and bends. Sometimes it is hard to tell for someone with an older mobile device, or inadequate vision.
Other than that, best app Ive used.

Dad of the year nominee about Knot Guide, v6.0