Just a guess but if I were to write it, I would create a table of points that map to a qwerty keyboard then map to a word. Then I would prerender as many word

Just a guess but if I were to write it, I would create a table of points that map to a qwerty keyboard then map to a word. Then I would prerender as many words as I can to seed this table. The algorithm would be about probability of shape entered. For example, if I meant to write the word 'hacker' but instead I wrote 'jsvlrt' the shape I've made would map to a similar shape in my database for 'hacker'. Add some creative elements for managing tolerances on shapes entered and you would probably have an impressively close product to this. As a side note: awesome app.