If you want to use it get an APK signer. you can get one from the android store. I haven't ran into any problems using them yet.
Let's not turn this into some kind of debate. I know (that it is well known) about android and the 2gb limit. Everyone knows that. However, I have a LOT of android users who download every release and they never have an issue. As I do not directly support android build (because I don't own an android and I am not an android programmer), I have no idea why most people have no issue with it, then every now and then someone (like you) says it won't work. Is it because you have an older model phone, or is the android version not the latest version? I wouldn't know even if you answered that - hence the reason I don't support it. I didn't want to even build an android version, but chose to do so because the renpy system has the apk builder already built-in.
Some devices designed for "gaming" may run at more than 2GB but run of the mill typically won't regardless if they're older or newer, and you really don't need to be a programmer to offer a compressed build especially if you have THAT many people on Android that play it as you say and seeing as this is the first release where the file size has exceeded 2GB, I would imagine nobody would be having issues.
Tell you what Bradd... I am running the compression tool now on the latest version. I'll rerun the build and upload it once it finishes (it takes a long time to run). However, you should know there is a chance the game is eventually going to reach a point where simply compressing it will no longer be enough.