You're at an airport with no services. You want to get on line to get a briefing and/or file a flight plan via iFly. Or you want to update the latest winds aloft, NEXRAD, ec, via Internet before you launch.
If you have WiFi only tablets, you can't do it, 'cause there's no WiFi around.
You could use cell phone data services, IF your smart phone is smart enough and has enough memory to run iFly. (Although if you already have iFly on two tablets, then you'll need a multi-license to put it on your cell.) If you're really geeky, you can tether your tablet to your smart phone so that iFly can get to the Internet via a cell data connection. (And I've done that before.) For those who can't tether, could iFly make a helper app that can live on a cheap smart phone, does only the Flight Plan proper part of iFly (that is, Briefing and File) and pulls the Internet weather info, and then sends that to your tablet in a burst? I'm thinking it would be a small subset of the iFly app, with the Wi-Fi transfer app.