Enable the plugin:

Add viimote.skprx to taiHEN's config (ux0:/tai/config.txt):
*KERNEL
ux0:tai/viimote.skprx
You need to refresh the config.txt by rebooting or through VitaShell.
First time using it (aka pairing):

Go to Setting -> Devices -> Bluetooth Devices
Press 1+2 (SYNC won't work) on the Wiimote during 2 seconds
The Wiimote will pair and connect automatically (don't press over it when it appears)
Using it after pairing it:

You simply need to press any button (instead of pressing 1+2) to connect it to the Vita.
Supported extensions:

Nunchuk
Classic Controller
Note: If you use Mai, don't put the plugin inside ux0:/plugins because Mai will load all stuff you put in there...

Changelog
v1.2
Add Taiko TaTaCon Drum Controller Support (thanks to @wolfarine) with the following button mappings:
CL-->Left
RL-->L1
CR-->Circle
RR-->R1

Name	Version	Released	Hits	DL Link	QR
viimote	v1.1	07/30/17	496	Download	QR