In reply to ScottTalbot:
If you don't intend to use it for navigation, but just want to use it to log routes, then get a GPS data logger. Because there's no user interface LCD, they're very cheap.
You can get them with Bluetooth comms, so, if you did want to use them for mapping, you could connect to them with your phone (though, if your phone has GNSS function, you wouldn't need to, unless you were really trying to save battery life; trading GNSS receiver power against Bluetooth comms power).
My experience with smartphone GNSS is that they're actually pretty good, because they often track GPS and GLONASS. And they can get A-GPS data from a mobile data or wifi link, and thus get a very quick fix.
There are apps to provide tracking using mobile data too: e.g. Traccar. You set up a Traccar server, and then connect to it using a Traccar client on your phone (Android and iOS).
https://www.traccar.org/
Post edited at 17:56