Rated 4 out of 5 stars

Hello!
1. Sorry for delay with answer.
2. Can't download a new version for FF from FTP that you say.
3. Now use this for my purposes:
https://addons.mozilla.org/en-US/firefox/addon/encode-decode-base64/?src=api

This user has a previous review of this add-on.

>> 2. Can't download a new version for FF from FTP that you say.

hmm, I can download :-) Anyway, new version (0.3.5) is alerady activate (sep/15/2015) on mozilla addon site, so you don't need to download at http://ftp.oops.org/....

Thanks.