I am using an open-srouce code from Google for an app called MyTracks.
I am getting this error when the original app is installed on the phone.
INSTA
I got this same error when I changed the package name in my app's manifest. This creates a conflict when you try to install the app again (with the new package name). The solution is to remove the old version of the app (that uses the old package name), then you'll be able to install the new version.