Very good, quite a few options. One issue I'm having is that I cannot do non-linear note editing. Eg) I cannot move the text cursor to the top or middle of a note. I have to backspace from the end of the note. A workaround is copying and pasting into notepad. Hope it's a bug. Thanks.

Very useful addition, highly personalized, but the synchronization does not work - I will try to synchronize the "json" file with third-party software. I hope to see working native synchronization. Thanks!

Unique and useful feature, but it needs to improve the UI.

Good. I tested all of stickies which works with 57+ and this one looks most advanced and stable so far.

Pretty good, but it would be better if it allowed a bit of formatting. The now defunct FloatNotes, which worked in a similar way, used Markdown – same as reddit, stack-exchange, gitbub, etc. – so it wasn't exactly sophisticated but good enough for creating headers, bold, italic, strikethrough, hyperlinks, etc.

Расширение позволяет оставлять заметки в разных местах (только на странице, на домене, во всех вкладках), но не хватает некоторых настроек, например нет определения уровней доменов, так например оставив заметку на домене "example.com" она отобразиться на "example.com/ru-ru/news", но не отобразиться на "lk.exmple.com". Можно свернуть заметку в меленький значок, но нельзя скрыть все заметки на всех сайтах (только временно и на одном).

That's the FF57-compliant replacement of the old but powerful Internotes addon I was lookting for.
Not tested thoroughly, but seems quite promising.
3 things though:
- Is there any data sent to the cloud when not logged in?
- Have you considered moving your code to GitHub to easy maintenance and support?
- Would it be possible to leverage "Mozilla sync" instead of proprietary cloud?

Thanks