Developers face relatively steep costs in getting the tools that allow them to create high-quality mobile games, complete with shadows, explosions, sounds, 3D effects and the like. Barriers include both the cost and the licensing terms, which can be confusing. As a result, companies behind mobile gaming engines have recently decided to make it a little easier--and cheaper--for indie developers to get involved. Mobile game engine firms Unity, Marmalade and Havok have recently started courting indie developers through a variety of moves; for example, Unity, which makes a popular game engine platform called Unity3D, said in May it would be dropping all license fees for the basic tier of its products and services. Find out more in this FierceDeveloper special report.