@meme Thanks to your plugin I was finally able to bring some order to my Kindle. Thank you!
It would be great if you could expanding your plugin beyond collections, into a Kindle Manager. By editing the system/com.amazon.ebook.booklet.reader/reader.pref file it is possible to change the fonts (without jailbreaking and using the font hack)[1], change the margins [2] or the justification [3]. It would be great if you could add a GUI interface for managing all these options to your plugin.
[1]
https://www.mobileread.com/forums/showthread.php?t=99355
[2]
https://wiki.mobileread.com/wiki/Kind..._Change_Margin
[3]
https://www.mobileread.com/forums/showthread.php?t=99661