1) Is it possible to add holding pattern by clicking on a map's object (vor, fix, etc. or just by making a long tap if there isn't any object at all) and setting desired radial and distance? Right now, if ATC will put you on hold there is just no way you can visualize if you keep yourself within prescribed (safe) limits.
2) Can you add an option to overlay my own set of approach plates (geo-referenced in GlobalMapper software & saved as .sqlitedb/.mbtiles format) over currently selected map? Just like in Garmin Pilot app.
3) Satellite weather overlay also would be a nice addition, although I can't really suggest any source of information, because I don't know how the data is going to be injected into the app. A few good website to check: windy.com, rainviewer.com.
4) It would be great if you can add approximate wind speed & direction derived from a groundspeed via couple turns (or else).