Google warned developers that they'd have to identify if an app contains any type of ads or be delisted. That has now been put into place to the benefit of Android users.
All free apps in the Google Play store now have a visible indication if a free app has ads. Google claims this is to provide transparency for those who don't like apps with ads. If that's you, simply move on instead of installing such an app.
It will be interesting to see if all developers support the ad tag, or if they will risk being delisted from Google Play.
Smartphone screens are small and when ads are introduced they either take a lot of precious real estate or they pop up and stop the app. That's why it's a benefit for Android device owners to see this tag up front before installing such apps.
Those getting free apps in the store should now slow down and have a careful look around before hitting that install button.
Prior to the ad warning, Google Play already indicated if in-app purchases were in any app.