You might remember hearing about Dawn of Titans a very, very long time ago. The title was announced in the spring of 2015, and has been in geo-restricted testing for about a year. Now, NaturalMotionGames has gotten the game built up to the necessary level to unleash it on the entire world. You can command your own sword-wielding giant after a sizable Play Store download.
Dawn of Titans is mostly a real-time strategy game. It's built around basic touch input to command legions of troops and giant creatures called Titans. The game relies on AI to handle the small-scale interactions and combat, but your strategy can be the deciding factor in battles. You can have thousands of individual units on the screen at once, but controlling them in groups makes it possible to keep everything straight. In addition, there's a whole world-building mechanic as you capture lands to beef up your kingdom and improve it with new buildings (there are hints of Farmville and Clash of Clans here). Over time, you'll unlock more soldiers and Titans to take on tougher enemies.
One of the reasons for the long delay in getting the full game out to everyone is the developer's decision to focus not only on PvP gameplay, but also on single-player quests. They found during the beta that many players burned through the single-player component too fast, so more was added. That's good, seeing as the campaign nets you in-game currency. Dawn of Titans is a free-to-play game that you could drop a huge amount of money on if you really wanted.
From playing it for a few hours, the IAP setup seems typical of what NaturalMotionGames has done in the past. There are some timers to deal with, and you need to spend the premium currency type to skip them. Although, Dawn of Titans seems to be reasonably generous with the freebies. It's not a free lunch, though. The in-app purchases range from a buck to an obscene $300. Please, don't spend that much on a mobile game, even a good one—and I would probably class Dawn of Titans as a good game based on my limited time with it so far.