Sometimes you need to be logged in the same place simultaneously, but the problem is with cookies that are stored and not allowed to do that.
Multifox is an extension that can access multiple accounts from the same site simultaneously and work normally in various accounts as if we were using a single account, only in different windows.
Once installed there is no configuration, we need only give the link or bookmark with the right mouse button and choose “Open in a New Identity Profile” to open a new window without the cookies saved. In this window we will login again with the second account and ready. We can do this, whenever we want, no limit on accounts that may be open.
We can also open another identity from File -> New identity profile.
