I was using an android phone for a while. Worked great but the 5.2" screen was a bit on the small side.
Tried an ipad mini 2 but found that too big and heavy.
So I took a punt on a 7" Huawei Mediapad T3 and it’s worked out great.
Cheap as chips too. Argos and Amazon were selling them for £59.99 recently.
I use mine as a dedicated display for the Mavic with nothing else running.
One restriction is that you have to use Go 4 version 4.1.9 as newer versions have video feed issues with the T3.
The latest version of Litchi works too.