One of the pillars of Android's success is its main app store, the Google Play Store, which has improved a lot in recent times. In the beginning it focused on improving the offer and security, but lately it is improving usability and information. Updating the browser version allows you to see if an application will have in-app purchases.
In the Play Store there are many free applications. However, many of them do not live exclusively from advertising, but you will have purchases within the application selling additional services that enhance or optimize the user experience.
This model in games is called freemium and it is becoming increasingly popular. The agreement with the user is to let him test the most essential or initial parts of the game and then offer paid extras that complement the experience. Sometimes, the idea becomes a bit perverse since the enjoyment of the application necessarily involves making a purchase and, therefore, some experts consider this model somewhat shady.
That is why it is essential to give this information to the user. It is also a very useful information for parents who share a device with their children. They are warned that there may be an additional expense and so they can take measures such as restricting purchases with passwords.
This possibility is more clearly explained in the browser version, but it can also be seen in the small mobile version with the indicative In-app purchases.
As we said at the beginning, the Play Store is becoming a more pleasant environment. Many renovations have been made to guarantee the security. The after-sales management to fix errors. And for tablet users it is now much easier to detect which applications will be optimized for the screen of their device.
The distance with the experience in iOS has been reduced significantly, and now it is a worthy competitor with its pros and cons compared to the competition.
Update: we apologize, we did not notice the indication in the Android application for being more subtle and not expressing itself in the same terms.