Originally Posted by jswinden
If you have never owned an Android device before the Fire, then you might not be aware that apps often don't really close when you exit them. If you are not careful you can wind up with a lot of running apps that can become a drain on your battery and slow down the Fire's performance. There are apps available that can help manage this issue.
Another way is to manually stop unnecessary apps from running by pressing Quick Menu --> More --> Applications then select Running Applications in the Filter by field. This displays a list of all currently running apps along with how many processes and services each uses.
To stop an app from running, select the app from the list and on the screen that is displayed press the Force Stop button.
Some of these probably should be left running like Settings, Amazon Device Client Platform, Kindle Keyboard, etc. But some are simply apps you opened hours ago and thought were closed when you exited them. Use your judgement and close the unnecessary apps and this will help battery and power performance.
If I may, please allow me to piggyback on this post. When you select an Application as described here, you can also choose to clear any data or cache for the App, and you can clear the Launch by Default setting. This last setting is particularly important if you decide you want to use one App over another. For example, say you want to use Opera Mini instead of the Stock Browser. If you don't clear the Launch by Default for the Stock Browser, when you try to browse with Opera it may kick you back to the Stock Browser by default. Sorry, I don't have my son's Fire in front of me so if I don't have the exact wording for the menus I apologize.