I have an iPad/iPhone aviation navigation app that superimposes weather data onto the sectional maps here in Germany. It is Internet based and cellphone reception is essential in the air. the coverage is good here so that is not a problem. It actually works with two of my apps ie Air Nav Pro and Sky-map. It has often gone through my mind if it wouldn't be the way to go on this side of the pond instead of relying on the jeppeson mapping. The sectionals are definitely cheaper on Air Nav Pro and there is more information on them too if one includes the AIP. This way you have all the VFR traffic patterns and taxi charts. I don't know how easy it would be to run it on the AFS system but it might be something to look into.