Our email address is contact@steamfriends.info and our Steam group is S.Friends. We also have a Discord server.
Past info such as friends renamed or deleted cannot be retrieved: we start to track changes from your friend list after your first sign in on steamfriends.info. Remember that your profile and your friend list must be public.
To avoid issues, a limit has been imposed for how many time you can refresh your friends history in a short period of time: you can refresh only 15 minutes after your login or after clicking the button "Refresh" in Actions. If you see the refresh progress bar appeareing and disappearing immediately, the limit is still here, please wait before trying again.
Steamfriends.info uses Steam's official OpenID interface to authenticate your Steam account. In this process you sign in with your username and password on the Steam servers, after that the Steam server tells us if you logged in successfully and returns your 64bit Steam ID. Your user credentials will not be shared.