What I have noticed in Accra is that there are multiple different street names-- names on shiny new signs and names on Google Maps.
As someone who has lived in Accra for a year, I would welcome a taxi navigation system.
This system will need some serious training and some free data for drivers.
Uber has been here for a while and, in my experience, the few Uber drivers that exist have difficulty reading their GPS on their phones and often simply do not want to spend their data on the GPS. Needless to say, most take forever to find you and, if they do manage to pick you up, have to ask you where you are going and ask how to get there --as if they don't have that information on their mobile phone!
If you've taken a few taxis in Accra, you'll quickly realize that drivers basically know how to get to an from the airport, to the US Embassy, and to the top four or five hotels. That's it. If you need to go anywhere else--even major/popular restaurants and cafes, you often have to direct them, turn by turn.
Regarding properties and lands, I think Accra is stuck. Land titles are so informal, insecure, and poorly regulated. This is one of the biggest land use problems in Ghana.
This post describes the problem. https://www.povertyinc.org/news/this-land-is-not-for-sale