The iPad has no built in capability to receive a transponder, 1090 ES, or UAT. It must rely on some other hardware receiver, not just an app, to display any traffic.
Most apps have reception from the GPS, which gives lots of interesting data. I am not the tech guru, but I can tell you from experience that when Alaska Airlines used to burn up my back side into Sitka the very expensive FAA funded Capstone box would not indicate their location, but my iPad would show them every time.
On to our actual discussion...
Between sun in a pilot's eyes, distractions, (two planes flown by students learning new things), and some bad luck this is a sad deal. As a pilot and instructor my true interest is how can we reduce this type of accident?
While we sometimes seem to think aviation is shrinking, we are seeing an influx in people doing quick schools with the desire to get in on the airlines hiring frenzy. Get hours, get ticket, get hired. What is worse is as urban sprawl continues, little airports are going away and neighbors are upping the complaints- forcing more restricted airspace use which compacts everyone into a tighter space.
As stated prior, if you read many comments on the YouTube, or on the Facebook forums it becomes startling how much basic knowledge is missing from so many. Worse, lots of them don't realize and probably don't care they don't know.
Bottom line for me is the intent to find the brightest lights I can find, make them flash, look outside, glance on occasion at any traffic data I might get inside, ask passengers to look for traffic and point it out, and just remember that even if I am paranoid, it does not mean that someone out there won't try to run me over again!!
FYI: I hate flying down the highway corridor from the north into Anchorage on a nice day. so many pilots busy finishing up getting their electronics tuned in and just not watching! Out of I think three trips last summer I had near misses on two, one of them we were watching the Bonanza for a long ways come our way and I kept edging away and it never saw us. mountains on one side and restricted on the other!