I have been trialling pilotaware, a non-commercial venture spearheaded by a BMAA member. You can build the unit yourself from parts you can buy off the shelf for about £60. It picks up ADS-B and can then display the data on say your skydemon (pic 1) or runwayHD and identifies them (pic2) It also picks up and displays anyone else who has the pilotaware box (pic 3).
It's an impressive initiative.
http://https://www.dropbox.com/s/ax300pcydxsj054/2015-06-27%2017.14.18.png?dl=0
https://www.dropbox.com/s/3kyanghgnw...04.20.png?dl=0
https://www.dropbox.com/s/79ggfn8l1w...56.59.png?dl=0