I found a cell phone game that is so similar to TU that it's almost scary.
The game is called Resources and is available for free on google play.
You play the role of a company and like in TU, you build mines to gather resources then use factories to create things from these resources and sell these items to other players or use them to upgrade your factories, warehouses, and create troops to attack and loot other players mines. The ultimate goal is to upgrade your headquarters building to level 10 and become the strongest, richest company. You start out with only being able to mine clay and make bricks, but as you level up from building mines, upgrading factories/warehouses, and completing quests, you unlock new factories and new mine types. It even has an inactivity timer, you get deleted if you don't log in for 7 days. The game is a few years old and is still somewhat small with I think a bit over 10,000 players.
Unlike TU, there aren't separate small servers.
The game is played on a single Google Earth type map that utilizes your phones GPS for real world position tracking.
All the various resources are available everywhere, but in varying qualities. So you will actually have to travel (yes, in real life) around your neighborhood/city/state/country to find good locations to collect the different resources, especially since mines can't overlap.
There is an open market where players can bid on goods to buy, along with a gov market that buys everything at a minimum price that changes based on the demand of an item.
Also, like TU, it is made by one guy in Europe.
Almost have to wonder if Mit had a role in this game :p
If you give it a try, feel free to look me up, my name in there is ZoricEnterprises