Advertisements have become the norm when you look at the lock screen of your smartphone. Instead of beautiful wallpapers and notifications,  some apps give users unexpected lock screen ads, which are often annoying.

Even though ads may some times present products which we haven't even heard about, they can be quite intrusive at times that people have started using ad-blockers to get rid of them. This time Google has taken a strong stand against those apps and decided to ban apps from displaying lock screen ads.

Google has set some very strict guidelines on how developers can use ads inside their apps. In its updated developer policy, Google specifically mentions that unless your app is specifically a lock screen app, you can't show ads on a device's lock screen

A picture taken on November 20, 2017 shows logos of US multinational technology company Google displayed on computers' screens.LOIC VENANCE/AFP/Getty Images

Here's the official announcement from Google's Developer Policy Center:

"Unless the exclusive purpose of the app is that of a lock screen, apps may not introduce ads or features that monetize the locked display of a device."

Google will begin banning apps which are violating the updated Developer Policy, and developers who are using them have officially been put on notice. However, this doesn't include lock screen apps or even those whose sole purpose is to pay you in exchange for showing you ads on the lock screen. Those apps are perfectly fine.

It's good that Google is making an effort to keep devs honest. So from now onwards, you can expect some lock screen ads from lock screen apps but not from other apps thanks to this new policy update.