I have been using foreflight (5 stars) and Jepp Mobile HD, which is fantastic as a replacement for paper charts but not a full fledge navigation app.
The Garmin app STINKS. While the user interface is good, i have no had the entire set of data mysteriously dissapear. Went to jump in plane this morning to fly home from last night and all of a sudden all of the nav data, charts, and maps are gone!!!!! So caution to you all as this has appaerently been happening to many others. Check that you have data before you plane on using the app. Until this is fixed, the app is useless and a peice of crap.
Now the currentversion wont even open. Crash crash crash. Back to foreflight and Jepp Mobile FD
Flying MD about Garmin Pilot, v8.4.3