How to publish an app on the iTunes, Android and Windows Phone store?

iTunes Store (iPhone and iPad)

To get started on the iTunes store you first need to create an Apple ID. You could use your personal Apple ID, but I would recommend creating a separate Apple ID specifically for your app to allow you to share your credentials with others if you want to, without having them expanding their music library at your expense. After you have set up your Apple ID you can apply for a Developer Account.

There are two types of programs, but unless you want to publish in-house apps (not in the store for the general public) the $99 / year program does the job. You’d better start soon: Apple reviews all applications manually. This might take a few days but can take weeks if they have difficulties verifying your identity. And keep in mind that the publisher names as you register will be listed with your apps.

This is your starting point: iOS Developer Program.

Google Play Store (Android)

For Android, the process is much easier as there is hardly any verification. Keep in mind that your Play Store account will be linked to your Google account. I would recommend you to create a separate Google (read: Gmail) account and register your Play store account with this email address so that you can share your Play Store credentials with other people without having them check your email too.

This is your starting point: Android Developers  (click ‘Developer Console’ in the right top corner).

Microsoft Windows Phone Store

In my experience, the process to apply for a publisher account in the Windows Phone Store isn’t as streamlined as with the Apple and Google stores. With Windows Phone, you are going to link your publisher account to your Live account, and again I recommend to create a separate Live account to allow you to share your credentials with others. 

This is your starting point: Windows Phone Dev Center