I downloaded a free app on my iphone (not sure if on android) called Magic Phone where the dc can get a phone call from Santa to say if they are on the nice or naughty list which can be personalised. There is also a parents area to set up the phone call but on the app it just looks like a countdown to Christmas with their stockings over a crackling fire!
My kids faces were priceless when a photo of Santa appeared on my as he was ringing, obviously its a pre-recorded message so they can't actually speak to Santa but any personalisation you make sounds like an elf 
they've had a nice list call and ds2 has had a naughty list call already but maybe he can pull it back before bed time 
Just thought it was a great idea and thought I'd share.