World of Dragons is (the first?) Massive Multiplayer Online Role Playing Multiplatform Game that can be played either in PC and mobile.
Mobile version: World of Dragons can be played for free until your character reaches level 10. After that, you will need an ‘upgrade scroll’, worth 50 LC, to continue playing for 10 more levels. Your character may reach level 60, so you could reach the end of the game by purchasing only 6 upgrade scrolls. After that, you will be able to play for free.
PC Version: The Lite version features the whole game with no restrictions. Developers are right now working to finish the PC Enhanced version which will feature mouse interaction and an enhanced interface.