On Sunday, February 5, 2017 at 4:43:05 PM UTC-8, Casey wrote:
Isn't that only in final glide that yellow, red, green shows up? Otherwise area within the flight alt circle are reachable.

If iGlide is properly configured, it will show the colors and altitudes for every landing site. The zoom level at which they appear, and the format that in which they appear at different zoom levels is configurable. If you have no airport database (or have airports turned off in the database) and no turnpoint database loaded (with appropriate TPs marked as landing sites) then I suppose nothing would show up. I am using the pro version, but as I remember even the basic has this capability.

Yes, these programs pretty much all do the same things, it is how they do it that makes the difference.