In my desktop Firefox I use Cookie Autodelete to keep a whitelist of sites whose cookies won't be deleted. All other cookies are deleted as soon as all tabs for a particular site are closed.
Android's Firefox, from what I gather, only give you two choices: delete all cookies upon quitting (not tab closing), or save them across sessions.
Unfortunately the extension above does not work on Firefox Android, and I haven't found any other alternatives.
Do you know of any alternatives or other solutions, to get a behaviour similar to the desktop one? (And also: how come that extension is not supported on Firefox on Android?)
Cheers!
FIY, people say you need Nightly Firefox for Android to install third-party add-ons using the collection method but you can do it on Firefox Beta too.