Folks at XDA developers have successfully ported LG G5 apps to the LG G2 and you need to do is flash the new files via recovery. The list of new themed apps include:
lgfilemanager and many others.
If you prefer 6 toggle UI, then flash this and for four toggle UI, flash this. Make sure you keep the DPI 480 otherwise, it would not yield desirable results.
That is it. Just keep in mind that you will CWM or TWRP custom recovery of LG G2 which will void your G2’s warranty but in 2016, it would have been voided by now so it makes perfect sense to load up and play with the new LG G5 features.