I'm not sure they'd ever have to update it. It's a myth apps need constant updates, and often that only applies to apps that do things they shouldn't or interact in specific ways with the OS or various devices. This app is peeling apart other apps to see how they work and what they do. That's about it.
Several of my low permission apps haven't seen an update in months, sometimes years. It's common on F-Droid. If it isn't broken, what's there to fix?
Given some apps being revealed here are basically BROKEN and/or do far far more than required to function as they are listed to function, it's no surprise they require constant updates eh?
Cash money says it would. It's just doing forensics. So I don't think the OS matters much in this case. Of course that would be something to test, but so far I've seen it work today on 2 different android versions, years apart.
The good news is.. Using this app, and other things, I've essentially got 75% of my phone in the green zone now, and it has caused me to remove a good number of apps that were being very very bad.
Check out F-Droid, so far 90% of everything I have scanned on F-Droid checks out as GREEN. Googleplay has some really dirty, poorly programmed junk apps from major players on it. Can you imagine how great my phone will function, and how much more private it will be when I am done this weekend with it? I can't wait.
I don't actually know the most current answer as I do not develop Google Apps.
However it used to be a violation of the Developer Policy Regulations. Sideloading is bad news because it bypasses Googleplay protections and screening, and allows a developer to basically side load updates, secondary applications, or modules. Which can be considered malware-like activity or could potentially be abused. I suppose it's worthy of some research.