Re: Printing from Android tablets
AFAIK since version 8 Android can print without drivers to Mopria certified printers:
WiFi Direct is supported only from 9 onward.
You may need to enable it from Connections under Options, there should be a sub-menu advanced (or others) network settings, and inside it a print sub menu.
Mopria is a business alliance among major scanner/printer vendors to develop a standard to scan/print without installing specific drivers. It's something alike a non-Apple controlled version of AirPrint, I guess.
It is true, that unlike Cloud Print, you can print only on supported printers.