A great review of Knots 3D from app review website dotTech:
Overall, I was very impressed with this app. There is a huge variety of knots here, and they are well-organized. The animated 3D diagrams make it really easy to see how a knot comes together, even if there are multiple strands involved.
As a history nerd, I particularly enjoyed the descriptions that come along with each knot. Having some background about how the knots were used and devised in centuries past is actually very helpful when you are trying to figure out what knot it best for a certain situation
Read the full review here: http://dottech.org/126483/ios-iphone-ipad-review-knots-3d-app/
After the iPad 3 became available late last week several users informed me of a bug on the iPad 3 making Knots 3D unusable. We worked on a fix over the weekend and have submitted it to Apple for review and approval. It typically takes Apple about a week to approve new releases and updates so hopefully the latest version of Knots 3D including the Retina Display bug fix for iPad 3 should be available around March 26. I have asked Apple to expedite the fix so it may possibly be available before that. The good news is the release also includes over a dozen new knots along with the fix including: Alpine Butterfly, Truckers Hitch, Palomar Knot, and more.
Thanks for your patience and understanding.