How an Android App can be publicized as most of the Android Apps are provided on Google Play Store?
Which SEO Methods are applicable for Android Apps on Google Play Store?
You can use SEO method for your own website, so if you are using those apps on your site then you can do SEO of your site so that it would have higher ranking in Google I would say.
Advertising is one option, the other is to advertise your app on various forums, facebook groups. Making youtube video is also a good practice. It avoids you negative reviews as user has already been aware of all app features.