In order to register as a game developer and publisher of the Android app for Google Play Developer account, you must pay around $100. But what if there's a tight budget, especially for indie game developers from the start? I want to know where can I find alternatives to publish and promote Android game apps with no registration cost. It is something like a stepping stone.
You can host the .apk anywhere online and just let the users download and install it manually. The down sides of this approach are many, for example discoverability (most people find all their applications only in Google Play) and lower level of trust (people are less likely to trust something outside of Google Play).
Having said that, this approach is used successfully by some apps, notably some betting companies do it this way due to Google Play's stance on gambling apps.