Promoting your app
There is not like 100% ways that your app can be promoted. The main way to promote your app is by using a store. There are 3 main stores:
- Play Store.
- App Store.
- F-Droid store.
This is the store of Google. In order to have your app there you need to pay a fee of 25$, it is a lifetime fee. The idea is to be able to clearly identify you in case of your app is doing something wrong. So to say, you are responsible for what you are uploading there, and if it goes wrong they have all the necessary information in order to go against you.
Here is the official link: https://play.google.com/store/apps
The App Store belongs to Apple. The fees are higher and you have to pay them yearly, so 99$ per year.
F-Droid is a specialized app gallery specialized in Open Source apps for Android and Android derived Operating Systems.
Here is the official link: https://f-droid.org/
Note that you can always promote an Android app on your own website, it is just that there are several warning notices from Android before installing it on your mobile. Note that for iOS devices the only way to install your own iOS app without the Apple Store is to self-signed your app.