Knots App for iPhone TrekCo November 24, 2010 Outdoor stuff, Technical We’re always looking for new things at TrekCo, and came across this new App – Knot Guide. Just search in ‘Utilities’ if you’re interested. Before this we’ve also recommended www.animatedknots.com as a great free reference about knots, so check these out if you are an instructor or just want to practise your climbing skills whilst sitting at your desk..