It's a lot of work getting books ready to be printed-on-demand, when you don't know what you're doing . . . But, future books should be rather easy. Javanese for Beginners should be on Amazon come Jan.
I suppose by 2018, it's entirely possible that a Javanese for Self-Study, book 2 might be completed and available to the public. I do this only for my own personal interest in and love of these languages, not for any personal gain (obviously, since there is little demand and nobody buying them) . . .
Anyway, I hope that if you do happen to be reading this, and happen to know someone who is interested in the Indonesian language, you'll do me a solid by shooting off a quick msg to them to let them know this joyous news.
Nov 2016, from Korea