Ask HN: Need tax help for CA LLC selling iOS/Android apps

last year, a friend and i started an LLC in california. we made a couple of mobile apps which we sell through apple, google, amazon, etc. shortly after that, i co-founded another startup, which has kept me very busy - too busy to think about paying taxes for my LLC. obviously, i'm a bit behind schedule here. i need help.

i've spent a few hours reading everything i could find about paying taxes on mobile app revenue, and how it applies to california LLCs. i found a lot of confusing and contradictory information. i could find no comprehensive, authoritative guide to paying taxes on mobile apps. most of the advice out there is written by people who are not tax experts. they seem to be just guessing. i don't want guesses, i want facts.

does anyone have a comprehensive, authoritative guide to paying taxes on mobile app revenue for both iOS and android and for US based companies? if not, can you perhaps recommend a tax professional that can help me? i'm wary of using just any old tax prep service, because i'm afraid they'll have no experience with mobile app developers. i would want someone who really knows what they're doing. thanks.