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.
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.