Hello,
Out of personal interest, I made a new drawing/sketching app for my Boox Note AIR 4C.
It uses the device specific system-brushes to get that zero-latency drawing that we all love so much.
I only tested in on a Note AIR 4C, because that's the only Boox device I have, so it would be good to collect some feedback from users on other (pen) Boox devices.
It's open source, free, simple but functional, and most of all: it offers a zero-latency drawing experience.
The build-in apps like Notes and Reader are great, but not really suited for drawing, because they keep every stroke as vector object, causing it to slow down as the drawing gets more complex.
This apps bakes strokes into a bitmap layer, so it doesn't slow down.
Source code and download links to the APK at:
https://github.com/steffest/Boox-EinkDraw/
It is based on reverse engineering the system apps, simply because the existing Boox development info online is incomplete, missing or just plain wrong, so here's a warm shoutout to ONYX or BOOX, the company: you offer best-in class e-Ink writing and drawing tech. Your zero-latency strokes are the reason we love and buy your products. There are developers out there who want to pour their resources into developing for your platform, but for *peeps" sake... why do you make it so hard to get the information we need to do so? Please, pretty please - update your dev channels with some up-to-date info and code samples, so we don't have to guess and/or decompile your apps just to see how things work.