I have zero knowledge but out of touch has packages divided into different installs...so is it really impossible to make an android
Basically what you do is.
1. You split the files so that you've got 3 different APK files: Resouce A, Resource B, App. They all share the same AppID/keystore.
2. Install ResourceA.apk, which copies all its files to the app savegame folder.
3. Install ResourceB.apk, which copies all its files to the app savegame folder.
4. Install app.apk. It's got all the rest of the files, and knows the rest of it's assets are in the savegame folder.
So why don't I do this?
Well, a couple of different reasons. The first one is that it's a big ass engineering task, and it will completely divorce the Android build from the PC/Mac/Linux one.
Secondly, Android is already 90% of the technical bug reports, and this kind of complex process is just begging for a ton of angry user reports/comments/reviews that "it doesn't fucking work, stupid dev, 1*". In a world where I've had people download the PC version, unzip it to android and complain they can't get it to work, anything more complex than "download APK. Run." is asking for trouble.
So. A ton of work for not much return. The honest truth is that I *should* be handling this by streaming the data from a server. I just need a way that doesn't break the bank on bandwidth.