Hi have airnav pro on my iPhone with the latest half mill vfr map it's pretty good although I've only used it once as I was only flying locally also for quick calculations on the ground I use pre flight it's on the app store then I have aeroweather which is useful
Again the screen is a bit too small for using it as a gps
Im thinking about using sky demon with a normal gps unit
There are loads on eBay for less than 60quid
Don't get me wrong the iPhone apps are good it's just the screen size is an issue