When we last looked at TWRP, the project had added support for a whopping 17 new devices. Granted, most of those were variations of three Samsung devices, but it's still impressive. Since then, three more devices have been added to the official builds - including the LG G6.
The G6 model in question is 'H870,' commonly referred to as the International model. This is a different variant than the US carrier and unlocked versions (H871, H872, US997, etc), so don't go flashing this on your shiny new G6 you purchased from your carrier. In addition, the 2016 Galaxy Tab S2 8.0 LTE (gts28velte) now has official builds. Finally, the 2015 Marshall London is now supported by the project.
As usual, you can download the TWRP recovery image for each device manually, or download the TWRP app (linked below) to flash the recovery from your phone and keep it updated.