Knots 3D

Occasionally, I find I have a need for a knot with a specific purpose. Today, I opened it up after updated and was pleasantly surprised with a couple of new additions. In my eyes, it's one of the best apps ever. They not only categorize by use, but also types, and the illustrated video tutorials can be sped up or slowed down for you to follow along. Categories include camping, fishing, theater & Film, neckties, decorative, boating, fire & rescue. Each one has a description of uses, common uses, video,and even a history and sometimes warnings!

Honestly don't remember if I paid for it or not, but it's been worth it. No ads either. Bonus news: it's also available on the web. Nice!