A free program for Android, by FDG Entertainment GmbH Co.KG.
"You can control each of the four characters, switch between them and even use their abilities to defeat monsters. There are lots of skills and items that can help you on your quest, so don't forget to equip them. You can also meet other people on your journey, so don't be afraid to talk to them and find out what's going on. You can even visit different places and find out what's happening there. It's important to remember that there is always a way to solve a puzzle or get a clue, so don't be afraid to talk to people and get help. It will also be useful to remember that sometimes it's helpful to talk to other people.