Before releasing Android application to the Play Store there are few things which you must take care. 'Anyway coming to the point before releasing any APK there are things which you consider before making final APK.
Check your code properly I mean review. Check your code throughly and ensure that you have written good and flexible code which will help you in future for debugging and maintaining etc.
Always create the release version of APK for uploading in Play Store.
Sign APK - create your own signature i mean create the keystore and sign your APK with this keystore which will give you authorisation that this app belongs to you. And most important keep this keystore safe which will helpful in updating your apps in future.
As your know the Login in Play Store cost around 25$ and i hope you can afford it.
Check for memory leak, memory consumption, configuration changes etc test and ensure your app is working in all the situation. Because the best quality apps make impression easily.
If you are going for an Ad in your app please read their documents and feedbacks.
Don’t forget to apply pro guard on the code. It wall let others not to decompile your code.
Write a brief about your app which attracts the user attention.
And once when your app is n Play Store and if anyone putting some comments on it try to response them as soon as possible. It will help you in user engagement. if you are getting negative feedback apologies to them and tell them you will be fixing soon and do the fixes as soon as possible.
Cheers :) #Go and get the user.