Gadget Pro

Every Android smartphone has an application manager that you can get to through the settings menu. Its usually in the top level somewhere, though it can vary a little by phone. (Samsung, for instance, has started splitting its app settings into different sections, showing feature settings for its own apps at the top level and requiring you to tap through to get to the actual application manager.) But once you get to it, youre at the heart of the matter. This is where you can see every application thats installed on your phone. And its a handy place to clean things up a bit should they go wonky. Heres whats up:

As you use applications, they start storing files for reference later. These files are stored in an app "cache." For instance: When youre using the Android Central app, itll save images and other pieces of the stories youve read so that they dont have to be downloaded each and every single time the app needs them. This saves you time and data.

Clearing app data is a little more drastic. Youre wiping the cache, but also clearing any and all settings that go along with that app. Youre basically starting that app over, from scratch, and itll behave as it did the first time you installed it. This is generally a last resort type of thing. If you clear app data on, say, the Facebook app, youll need to log back in. If you clear data on a game youve been playing, youll be back at the beginning, as if youd never played it. (And lets hope that game is properly saving your place to the cloud.

So when should you clear an apps cache manually? Chances are youll never need to. But should an app start to "feel" sluggish or otherwise start misbehaving, this is where Id start. Clear the cache.

And should an app really go haywire — or if you just want to start it from scratch — you can go all out and clear its data and start over from the beginning. Just tap the "clear data" button. Youll get a warning asking if thats really what you want to do. Confirm that, and youve reset the app to scratch.