Hi,
I had some problems with getting an accurate position myself. I posted a question about it (didn’t got much response 
)
here is the link Geolocation and accuracy
In short getCurrentPosition isn’t always accurate because it returns a result to soon.
The guy from the repo wrote a function getAccuratePosition which uses watchPosition to get a better fix.
If you like to know if a user has changed position watchPosition is the way to go. It creates a watch which updates if the user moves.
Can’t give you proper code because I’m still wrestling with it myself
The getAccuratePosition works though tested it with 20m accuraccy.