Internal (indoor) aerials are very hit and miss. If you live in a very strong signal area and the room is in a side of the property that faces the main transmitter then they can work just fine. With a weak signal strength area and/or the room on the wrong side of the house then its another story. That's what there's so much variation in the reviews of these things. A much better option is a short Log Periodic aerial. They're compact and give far better results than the indoor aerials with built-in boosters.
The newest
Now TV boxes have added an aerial input alongside the Ethernet and HDMI sockets (
see image here). This means that instead of just just relying on the main catch-up TV services (iPlayer, ITV Player, All 4, My5 etc) you can now watch live TV so long as there's a working TV aerial connected to the box. That still means you have to have a working TV aerial connected to the box, and in your case if there's a working TV aerial connection then you might as well plug it in directly to the TV anyway
AFAICT, the
Now TV box doesn't support live Freeview channels broadcast via the web. This would be services such as
TVCatchUp They're free to use (but you do need a TV licence to view) and work from a web browser on a laptop, a PC, a tablet or a smartphone. Devices that support casting can be used e.g. Google Chromecast. So you would bring up the TVCatchUP site on the web browser on a phone, then cast that to a Chromecast which is connected to the HDMI socket of a TV. If that all sounds like a complete faff then you're right. Just run some coax from a splitter from the existing aerial feed. Much simpler IMO.
Sky RF2 link is another solution, but basically that's just a bit of coax to take the aerial signal as looped through the Sky box up to the other TV. You're still running coax, and all you're getting is Freeview plus one analogue channel which mirrors what the main TV is seeing from Sky.