Hey again, @SkyFlower.

Thank you for getting back to me. I'm unable to make any specific recommendations, as there are many apps in the store; however, I can confirm there are plenty of apps that do integrate with the desktop version. I recommend checking with PayPal directly, as they might be able to suggest one such solution that allows their program to link with ours. 

I hope this information helps. Feel free to reach out to me if you have any additional questions.