How to find a paid version of an app?

Not every developer creates and puts a premium version of an app separately into a market. A developer can have a single app but have mechanism to make the user unlock certain parts of the app by paying for it. This is called in-app billing.

Google in the document In-app Billing noted:

In-app Billing is a Google Play service that lets you sell digital content from inside your applications. You can use the service to sell a wide range of content, including downloadable content such as media files or photos, virtual content such as game levels or potions, premium services and features, and more. You can use In-app Billing to sell products as

• Standard in-app products (one-time billing), or


• Subscriptions (recurring, automated billing)

_{(Emphasis mine)}

The app Clash Of Clans supports in-app billing.

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If a developer (any individual or a company) did put a premium version of an app, then the easiest way to find it is to open the developer's page and go through all of their apps currently published in that market. It makes sense that both the apps would have the same developer behind it or at least the same public name (pen name) of them.

In your particular case, the app Clash Of Clans is published by Supercell and their page doesn't show any premium version of that app.

It is easy to search the developer's page by using Play Store from a web browser. Simply click the developer's name and there you go. Same cannot be said for Play Store app.

Edit:

In Play Store app, use this query:

pub:PUBLISHER_NAME

PUBLISHER_NAME is case sensitive here and should be replaced by name of the publisher of app, so ELECTRONIC ARTS would work but not Electronic Arts or any combination of uppercase and lowercase letters in that name.

Example:

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Source for edit: Linking to a Product List