If they're in the open and not behind furniture, that's an extremely good sign.
The basic ingredient in gaining the trust of feral cats is TIME. Don't pose any kind of threat to them. Offer food, and a litter tray near to where they hide, and leave them alone. It can take weeks/months, but they'll come round when they feel safe. If you approach them, try to touch them, or try to force the taming in any way, they'll see this as frightening and you'll be set back in the domestication process.
It took me six months to gain Polly's trust. One day, of her own accord, she jumped onto my lap. I didn't make a big fuss of the event, just let her sit on me. She would have cringed if I'd tried to stroke her; so I waited until she nudged me.
She quivered behind furniture for ages.
I don't think you'll have such a long process, especially if they're watching tv with you!