I bought it to run on a Nexus 5 to replace a stand-alone Garmin GPS that bricked itself. I have used it frequently and it works well. Do not use it on a phone that only has a small amount of RAM - as with Navfree, it will tend to crash frequently on phones that have less than 1GB of RAM. Maps seem to be upgraded annually or thereabouts. Haven't had any real issues with it that I haven't also had with stand-alone GPSs. I went for the worldwide maps version. Overall, it's one less separate electronic item to cart around.
PBW