For creating a new account, A dialog box is created so that when users initially click on the Create New Account option, A dialog box will be opened listing all the email ids stored in his smartphone and a "other" option too, which when clicked will pop out a dialog box having a editText in it where the user can write his alternative email id. The user can click any of those and his account will be created just like in the previous versions of the companion app.
This feature will be user friendly because they wont have to write the whole email, just click on one of those emails listed in the dialog box.