Log in to Invoice Maker with an email address you've used at the signup. It's the email address of your account.
The email address can be found in Settings
Also, you can log out from the app and log in with a different email address to access a different business.
You can log in to more mobile devices at the same time but perform a synchronization before starting to create a new document.
Invoice maker is only available on mobile devices. There is no computer app or website available.
EXPIRED LINK
If a you see a message about an expired link
delete the email
go to the login screen
enter your email address again
you will receive a brand new link
should is still not work, delete all login emails, wait for 30 min and try to log in again