I am an app developer. Can I use an APK downloader to artificially increase the downloadcounter of my apps?
TLDR; Nope, you can't (and you shouldn't either).
Yeah, I know, money makes money and it’s virtually impossible for small app developers to compete with the top dogs on Play. Can’t blame you for wanting to game the system by using an apk downloader to boost your app’s popularity with a couple thousand fake downloads. (Un)fortunately, it’s not that easy.
First of all, “download” doesn’t equal “installation”. Or better said, not every download results in an installation. Maybe the app is too big in size, the internet connection too slow or the battery too empty. There are dozens of reasons why a download may fail (and no reasonable way for a webserver to detect that). Even if the download succeeds, there is still no guarantee, that the installation will succeed as well. Maybe the user cancels it after thinking twice about the requested permissions or maybe there simply is no more free space left on the device.
Play only counts downloads as installations when the Package manager confirms it via the official Google Play app. Should Raccoon fake such a “installation succeeded” message? Good question! On one hand, it’s pretty arseholic to deny app developers a well earned +1. On the other, such a function would be wide open to abuse, which brings us to the issue at hand.
Artificially boosting an app’s installation counter is a violation of the Google Play TOS. Mess it up (e.g. by simultaneously reporting hundreds of installs from the same IP address) and you put your own developer account at risk. Mess it up on purpose to put up a competitor’s developer account at risk. Google does monitor spam. I can see that with my own apps that occasionally get Installations deducted. I assume, those are the work of ASO clickfarms trying to create white noise by installing random apps in order to hide the one app, they are actually trying to promote.