litchi from what i know uses wifi only to get the telemetry and data.. but if you try to use otg you only get video and the mapp not battery percentage etc.. plus its paid 25 bucks.. dji missions you can do it with cell phone data or at home... save the missions go offline at the feild make sure to open dji go mod and go to where you plan to fly or a back up location incase you cant fly there.. and zoom in to store the map in your buffer... then you can fly offline with no cell phone data... and open the tap menu that lets you do missions in the modded app.. launch the drone then find what you names it and press go and it works...... theres not many choices maybe 3 and 2 are paid.. and litchi well in my opin sucks...ive heard bad things like dropped video etc ..... do what i do i use the stock app on a ipad for fun and if i want to fly around with missions i use a cell phone with android....
