Thanks for this addon. I'm looking for it as a substitute of Clipboard Plus in quantum because it seems to me the developer is very active here.
I've two requests, hoping you could add that. First, I think a keyboard shortcut (maybe customizable) is necessary for a comfortable use of the functionality. Clipboard Plus used ALT+A, but maybe there could be other comfortable options (maybe ALT+C, easier to remember?). Second thing, I think that the better way to separate the copied elements would be a custom string, including special characters such as \n, \t, etc... For esemple I often need to use "; " as separator, other times I need tab, sometimes I need double new line. Custom separator (and obviously a way to easily change it) would save me a lot of time.
I'm giving four stars, but I'll edit in five if the addon will be improved.
Thanks!

May not work for me. I'm using Mac OS 10.11.6 and Firefox 61.0.1 and I get no menu indication that this app is installed although Firefox indicates it is. If it is supposed to work, can you give a detailed instruction of how to use it? e.g. highlight text, click on Edit menu, etc. etc.
rwgro@yahoo.com

I still use FireFox 56, to keep all my old addons.
Append-To-Clipboard only seems to work in version 1.1 with FF56
Version 2.0. of a2cb doesn't seem to append anything in FF56.

So 1.1 would be okay 4 me, but here the context-menu isn't cascaded, which I find nicer.
Anyhow good extension. I was looking for that one for a while.

As a suggestion, I think it would be fine if the user could configure his own separator,
Sometimes for example you want to create lines for a CSV file, then you need , or ;
Then again tabs would come in nice. Or whatever. There's a lots of usecases for appending text...

Even cooler if you could do the different types of appending using hotkeys such as Shift+A for append without sep, Shift+Ctrl+A for append with linebreak .. etc...

Wouldn't copy and append from a text box on the web page. Reason for 1 star is that it is still in the context menu after uninstalling and restarting Firefox.