I'm not sure about the specific apps that can be used to create GPS autopilot missions with the Yuneec Tornado H920. But have you tried looking into drone mapping and surveying apps? These apps often have features for creating and executing automated flight plans for mapping and surveying purposes, and some may be compatible with your drone model. Alternatively, you could try contacting Yuneec customer support or forums to see if they have any recommendations. Nowadays, forums can be very helpful. They helped me find some good tips and solutions for my issues, including what games pay real money. So, they're worth taking a look at.