It could even have a small screen and physical keypad. I don't think any such phone exists, but it would be an interesting exercise to chop down android to those elements.
If we're moving towards wearables, I imagine that many narrow use cases might move towards watches, etc, that seem like tethered devices anyways.
It's a little too old to do 4g, but the Nokia phones which ran s60 / Symbian would do what you want. Many of them had GPS and could run Google Maps, most had wifi, and all were solidly built with several days of standby time. Look for the Nokia e71, which was probably the best one and I still see it for sale here and there.
If you want something made in the last couple of years, Nokia's Asha line of phones would probably work, though I don't know if Google ever made a version of maps to work with s40-based devices.
1) 4G+Tethering 2) Contacts Sync 3) Maps/Nav 4) Email/SMS
It could even have a small screen and physical keypad. I don't think any such phone exists, but it would be an interesting exercise to chop down android to those elements.
If we're moving towards wearables, I imagine that many narrow use cases might move towards watches, etc, that seem like tethered devices anyways.