you to download videos from YouTube and watch them on the go. Remember to do this over a Wi-Fi connection! Chronic music streamers should check out the offline playback modes of their favorite streaming apps. Both Slacker Radio and Spotify offer offline playback modes, though you must be a paying subscriber to use them. Slacker Radio's offline playback mode caches your personalized radio stations, while Spotify's offline playback mode downloads all of your playlists so you can listen without a network connection. 8. Don't Obsessively Clear Your Cache Another mobile browser tip: if you don't clear your cache often, you'll end up using less data because your browser won't have to constantly redownload images and other Website assets. If you like to visit the same Website often, obsessively clearing your cache forces your device to redownload the same basic information each time you visit the site. It's a waste of data, and if you use a task-killer app you might be wasting that data without knowing it. That's because lots of Android task-killer apps automatically clear your phone's cache to free up memory. Clearing your cache occasionally is a smart idea, but if you rely on a task-killer app, you're probably doing it too much and wasting data. Since you own an Android device, it's a safe bet that someone told you to download a task-killer app, such as Advanced Task Killer Free , to maximize your battery life. However, PCWorld tests have shown that task killers don't really work