Or even better, a web based one?
100% client side, 100% browser based, made with polymer 0.8 i think.
You can see the code at https://github.com/Klathmon/stitchpics
It was written kind of as an exercise to learn polymer at the time, so forgive the questionable decisions in architecture.
All the code is at the github link above, but it's using Google's Polymer (version 0.8 or 1.0 I can't remember exactly). It used the "paper elements" elements from the Polymer team.
It is NOT idiomatic for that framework, as it was my first time learning it and it was going through a lot of change at the time (due to it being developed in pre-1.0).
Aside from that, it's just SASS, ES2015, Web-components, Web-workers, and a bunch of TypedArray usage.