Gestures/drawings are matched to app/bookmarks using a finely tuned multi-stroke gesture recognition library I wrote (
https://github.com/mhuusko5/Cocoa-Multistroke-Gesture-Recogn...). This uses a tweaked implementation of the $N (golden section search variant) recognition algorithm (
https://depts.washington.edu/aimgroup/proj/dollar/ndollar.ht...).