NQ Mobile helps fight mobile malware on Android devices and is popular enough to have been downloaded over 100 million times. Solutions like this are popular, of course, because Android and its Marketplace haven't been the safest environments for mobile end users.
NQ Mobile's engineers scour the web for malicious software. The company also has automated web crawlers doing the same--looking at web sites, curated app stores, and other aggregation sites. Users can then whitelist applications based on the date NQ Mobile provides, or avoid apps that may be suspect.
[ Read about some of the ways 3LM could bolster security in the Android Market. See Wanted: Secure Android App Whitelisting.
Each time a user boots up the device, NQ Mobile scans for any problems and continuously scans for new problems. It also has several privacy features, many of which can be accessed in the basic Android settings, but NQ Mobile makes this easier by pointing out some of the privacy issues that might be a problem.
In the video demonstration below, you'll see how the initial phone scan works, get a look at the product's Privacy Advisor, and learn about some of its settings. The app is free in the Android market, but there is also a premium version that provides automatic updates to the virus database and several additional privacy functions.