You cannot use desktop download software on an iPad or any other mobile device. If you want to use desktop download you need a full PC or Mac.
https://turbotax.intuit.com/personal-taxes/cd-download/
If you only have an iPad, you can use online TurboTax. With online, you get one return per fee. Federal and state returns have separate fees with online.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**