Yes, log out of Brewfather and go to the login screen, write in your email in the email field, and click the "forgot your password?" link. You will then get an email to set your password. After you have set your password you can log in with that email and password combination. If you want to change the email-address tied to you account you can do so in the manage account page found by clicking your portrait/email/name in the menu.
Easy! Click the scale icon in the equipment section of the recipe designer.
You can also just change batch size or efficiency in your equipment profile within a recipe, click save and it will ask you if you want to scale the recipe to match the new numbers. Also - if you change to another equipment profile it will scale to match it also!
Basically you export a BeerXML on your phone and open it directly in the GF Connect app. On your batch click the menu button in the lower right, click export, select BeerXML, the file will show and you should get an option to open the file in your GF Connect app.
iPhone example. Slightly different approach in Android.
Then you just start brewing!
See the Tilt Hydrometer page for setup instructions.
See the iSpindel page for setup instructions.
See the Brewpiless page for setup instructions