I'm happy to hear you're such a big fan of the game! Unfortunately I cannot give you a concrete release date at this time, but I can assure you we are working hard to get new packs released as soon as possible.
The Android version came out much later than the iTunes version, it is still behind in available content, but rest assured we are pushing to catch Android users up with Apple users.
Apple users have access to more packs because the app existed on iTunes for over a year before being released on Google Play. As mentioned above, rest assured we are working our hardest to get both Apple and Android users on par.