How do I stop all running apps in the Samsung Galaxy S3? Device: Samsung Galaxy S3
Android: 4.1.1

I need to stop all running apps for an app, but how do I do that with one click? Is it safe?  Does the S3 have a tool?
Long-press the home button.
You should see something similar below.
NOTE: It is from a Samsung Galaxy S4, but S3 should have it also.
Then, click the 3rd icon (lower right).

YES, it is safe. It will close all open apps.


Screenshot (click image for lager variant)

UPDATE #1: Just to clarify Izzy's comment, he's partially right. Clicking the button will not close all running apps, but it will close all apps have you have manually opened. e.g. If you opened 3 different browsers, and clicked the button above, those 3 browsers would close. However, it will not close background processes / services that are running (e.g. AdBlock, aCalendar+, etc)