I bought an Acer Iconia 8" tablet refurb for $62 on Amazon a few months back, and while it technically "worked" with DJI Go 4 and Litchi, I dealt with lag, many app crashes, and aircraft disconnects when far out with my Mavic. It is good to be able to fly with a bigger screen than a smartphone so you can see more, but the lag and slow tablet finally got enough of me. I have all Android stuff and am not a big Apple Fan due mainly because of how locked down their products are, if you can get your hands on an Nvidia Shield tablet I hear that one works very well, since it's a gamer tablet and its fast. DJI Go 4 and Litchi are pretty processor intensive apps with all the things going on simultaneously in them. I even tried my kids brand new Amazon Fire HD 7 tablet, it was even worse than the Acer. I'd suggest spending a few dollars on a good tablet, maybe a newer Samsung Tab 3 or something similar. You want something with a decent amount of RAM and good fast processor. I think also you may have to go to apkmirror and find an older version of DJI Go 4 in some cases if you do find a cheap Android tablet that can run the app.
And for me, I came across a deal I couldn't pass up on a ipad
Air 2 10", a $500 tablet for $100 new in the box unopened. I haven't suffered a single app crash in dozens of flights, many long distance. And no more disconnects. With DJI Go 4 for some reason the app works flawless on Apple products and hit or miss on Android. My phone is an Android based LG V20 which is really fast, yet I have app crashes with it, and its a supported device on DJI's list. Also, if you buy a tablet and its not on the list DJI put out, you get 0 technical support from them. (My v20 is supported and I got barely 0.1 technical support so lol) After going to the ipad there's no going back to that Acer, night and day difference. My Mavic is too expensive to fly with all that lag and app crashing for me.
Here is from their website for supported devices:
Mavic – Specs, FAQ, Tutorials and Downloads
APP / LIVE VIEW
iOS Version v4.1.5.
Requires iOS 9.0 or later. Compatible with iPhone 5s, iPhone SE, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone 7, iPhone 7 Plus, iPad Air, iPad Air Wi-Fi + Cellular, iPad mini 2, iPad mini 2 Wi-Fi + Cellular, iPad Air 2, iPad Air 2 Wi-Fi + Cellular, iPad mini 3, iPad mini 3 Wi-Fi + Cellular, iPad mini 4 and iPad mini 4 Wi-Fi + Cellular. This app is optimized for iPhone 7, iPhone 7 Plus.
Android Version v4.1.5.
Android version 4.4.0 or later. Compatible with Samsung S8 ,Samsung S7 edge, Samsung S7, Samsung S6, Samsung S5, Samsung NOTE4, Samsung NOTE3, Samsung tabs 705c, Ascend Mate 9, Ascend Mate 7, Huawei P10 Plus, Huawei Honor 8, Huawei P8 Max, Vivo X7, Xiaomi 5, Google Nexus 6p, Nexus 9, Google Nexus 7 II, LG V20.
*Support for additional devices available as testing and development continues.