idk, I just have a few cases
an Obliq, a generic clear TPU from Amazon, and a cheap ass case I got from AliExpress.
I wouldn't mind picking up an extra battery and battery charger since they were so useful on my V10 but the battery life on the V20 is better so I don't need that.
As for generic accessories/stuff that works well with the V20:
- Decent headphones sound bamf on this phone if you enable HiFi and are playing something that is decent quality. I have some Sony over-ear headphones that were ~$100 and they sound BAMF with Spotify on Extreme quality.
- Dollar Tree selfie stick + tripod. Buy a dollar tree selfie stick and unscrew the phone mount from the top, throw away fgt stick. Then screw that onto any camera tripod and BAM phone tripod. Now you can take long exposure (up to 30 secs, not bad for a phone) shots with your V20. You can capture stars, light trails of traffic, do light painting, etc. with this.
- USB-C goodies. I've tried a few USB-C things on my V20 and they all worked great. I tried an adapter that had 4x full size USB ports, I tried a straight USB-C > full size USB, and I tried a USB-C dock that had HDMI, Ethernet, and a couple USB port and that worked also. There are lots of adapters on Amazon with different combinations of ports and they're pretty useful for video-output, ethernet, plugging in mice/keyboards, usb sticks, etc. Kinda cool.