E ink support
Support or improvement for e ink note taking devices with active stylus, (sony epd, onyx boox, bouye likebook), this will require the app to not redraw the whole screen as an LCD display but as an EPD (and allowing some ghosting to reduce stylus latency, as do the native notes apps on these devices)
Also a grayscale UI, with maybe showing color names when hovering the pen over the available colors.
Andrew Whaley commented
Yes, please. The native notetaking apps work with no lag but lack the features of established notetakers like Squid. Seems to be a huge growth area for eInk devices, so the first regular Android app that caters for these will do well.
Kevin Bhasi commented
Yep. I use Squid on my Likebook Mimas as the built-in notes app has a bug that can result in lost pages, at least on firmware version 1.0.2 (current version as of posting this).
I'm hoping there would also be an option within the app to change the top bar from blue/white to white/black.
I know that low latency ink on e-readers running on Rockchip RK3368 is possible, as the built-in Likebook notes app does show that. I even opened Floating Apps (another app that provides pseudo multitasking) on top of the note editor, and watched as my pen strokes went right through the window, so it must be triggering some kind of ink mode on the EPD controller that allows the user to write with the active pen (which uses Wacom EMR, like with Samsung S Pen), and after a few seconds, the contents of that pen ink buffer (I don't think that's the correct term for it) would then be dropped onto the app below.
However, with Squid, some additional code may be required in order to flush the contents of that ink buffer before panning and/or zooming, as well as selecting, adding text, and/or drawing shapes.
What I can also mention is that the KOReader dev team was at least able to figure out how to do the screen refreshes, though.