I would suggest that you take a look at the courses on Udemy.com They have some very good how to build mobile apps courses. If you are a programmer this should be a great way to get started. You can also look at Chocolate Labs or James Carters BlueCloud courses. You could look at Zapper for a build it yourself without prgramming app system or take a look at Buildbox (they have a monthly subscription but you can only buy it at certain times) for building games.