Maybe you only just became security-conscious after reading the latest news about Trojans making life miserable for Android users, or maybe you're trying to help a friend who's nervous about their data. The tedium induced by checking through every installed app and confirming its security might drive some to go for a factory reset, but a free app called PermissionDog lets you scan your device for any app that might cause problems, then confirm whether you trust it or not. Here's how to use it:
Install PermissionDog and fire it up. It will take some time for it to scan all your apps.
Once it's scanned, select the "Applications" tab, then tap the Menu button and select "Sort by danger" to see which apps could potentially do the most damage. In the example below, I know and trust the top apps in the list; if you see something unfamiliar or an app you never use that's got access to spooky levels of permission, you may want to uninstall it just to be safe.
PermissionDog can also monitor in real time and can alert you to apps running in the background as well as what permissions they are using. If you think something is fishy, this is a great service. It's on by default; select the "Settings" tab to turn it off.
Of course, there's a certain amount of subjectivity in scoring each permission, but for the most part, the developers did a good job, and PermissionDog is a great place to start your commitment to securing your device.