I've got four Google Chromecast 2 devices for sale. £15 each.
You can watch Netflix from your phone or tablet on your TV. View photos and videos from phone/tablet on TV.
Lots of uses - You can Goggle it to find out exactly what they do.
The Chromecast plugs in to a HDMI socket on your TV, and uses a USB port from your TV, TV box or modem to power the Chromecast device via a cable. You'll need to provide your own micro USB cable, as I've lost the original, and if you don't have a suitable USB port near your TV you'll also need to buy a plug in USB charger.