OpenTTD is the Android adaptation of the open-source 'remake' of the classic 1995 strategy and management game 'Transport Tycoon Deluxe'. In this game, you create a transportation network between different cities, aiming for the success of the network so that you can make a profit.
A typical game of OpenTTD takes place along a period of time that stretches from 1950 o 2050, meaning that you have one hundred years to score as many points as you can. This is achieved by having a good, constant stream of income, a large fleet of vehicles, and a large amount of goods delivered to their respective destinations.
In the beginning of the game, you can create highways and trucks to establish basic commercial routes that won't give you much in return. As you progress through the game, you'll be able to establish commercial maritime and aerial routes which normally provide you with a wider profit margin.
Of course, as the game advances and the years pass, technology also improves. So be on the lookout for new transportation technology as it arrives, as you want to be first in line to take advantage of any new innovations.
OpenTTD is one of the most famous free management games out there for a reason: it's excellent. The controls for this touchscreen version are a little more clunky than the PC version, but it does provide various control systems for tablets and phones of different sizes.