Here are a few of the fixes that should show up in today’s builds:
Bug 1229023 - Fetch and expose Firefox Accounts profile data
Bug 1224701 - Sending Email Notification bar is empty without text
Bug 1146265 - [Aries][Nexus 5][Contacts] Creating new contact page does not fit the screen width.
Also, in today’s build I see signing in to Sync is working. If you were having problems with it before, try today’s update and let me know if it’s working for you too.