Hey,
I just downloaded and installed the app, everything seems to be working so far. But I opened the .ini file at /media/com_easysocial/apps/user/blog/en-GB.plg_app_user_blog.ini and started to translate the items inside that file.
No matter what I tried, the changes had no effect. I do not understand that system.

Usually I took a language file, translated it and then I was done.