Are you wondering how that mysterious icon ended up on your Android phone’s start screen? Annoyed at the ads clogging your notification bar? You aren’t alone. Thousands of Android apps now include software that shoves marketing icons onto your phone’s start screen or pushes advertising into your notification bar–and many of the apps give you no warning about the ad invasion.

Sleazy_Android_AdsMany of these ads come from mobile marketing firms such as AirPush, Appenda, LeadBolt, Moolah Media, and StartApp. The companies work with app developers hungry for some way to make money from their smartphone software. By bundling their adware into popular Android programs, these marketing companies say they are now pushing ads to millions of new smartphones each week.

Smartphone users generally hate the swarm of marketing on their touchscreens, but the approach is growing fast. One of the companies, AirPush, says 800,000 people a day download an Android app with its adware inside–up from 250,000 just three months ago.

Click here to read the complete article on PCWorld.com.