Recommend EGM2008

[mikeglee]

I would encourage you to go all out and implement EGM2008. It's what iPhones use, and it would be great for Android devices to be able to achieve the same level of accuracy.

https://developer.apple.com/documentation/corelocation/cllocation/1423820-altitude

[Cat]

I close this issue because it is a duplicate of the issue #149
Anyway, thanks for the suggestion!