But my app is free...

Apkfiles is quite popular in China, where Google Play isn't always installed on android devices. Similarly, around 30% of users in the western world actively avoid Google Play, with another 10% refusing to sign in but allowing the services to run.

I'd make use of them - otherwise someone else is only going to drop a copy that may or may not be malicious and/or may or may not be pirated.

I'm quite pleased to see someone from one of these sites approaching developers, actually.

I received the same too. And I actually did upload, because why not.
You will occasionally receive messages of renewing your app as well.

@monr0e @boo1997 I'll take a look at their website and do some researches then!

@Letmecode thank you!

I always use apkmirror

@inpothet I tried to upload to APKMirror but they never published my apps

I looked up your apps in the play store and have to say the german translation of the description is really bad... I'm also a young dev, maybe we can support each other a little. I could translate your descriptions to german and english if you want :)

@cr78 sure! Contact me, you can find my email on the Github profile.

@StefanH that's what scared me mostly.

@StefanH Well you are only sending the apk, which can be extracted after installing through Google play store.

Therefore you are not giving them anything they wouldn't be able to get in the first place if they really want to.