Groundfloor users can use their Groundfloor login credentials in the Stairs app and do not need to register for a new Stairs account or link a new bank account. Upon logging in to the Stairs app, a Groundfloor user's linked bank account will automatically be available in the Stairs app for funding.
You can now also transfer funds directly from your Stairs account to your Groundfloor account, but it is not possible to transfer in the other direction.