You cannot use a desktop version on a mobile. Are you referring to a TurboTax Online version, which you have logged in via mobile and then by using your computer?
If that is the case, make sure to use the same log in and continue the same return and you will not be ask to pay again. Please note, the Desktop version is a downloadable version and can only be installed on a Windows OS.
Thank you for choosing TurboTax.
