There is no Android user who has not noticed the slowing down of Android smartphones after a few days. Many people suggest that restarting the phone every few days is a good way to keep it running fast and smooth. This is because some apps keep running in the background and consume a lot of RAM as well as hog the CPU, and when you restart the phone most of these apps are closed down – making the smartphone a little faster. Although Android itself is a very smart operating system and automatically kills the apps and services running in the background after some time to free up the RAM and processing power as per needed, but if you do not want to wait for the Android system to stop the apps running in the background, then you can always use the in-built Task Manager to stop these apps manually.
For some reason Android does not provide any icon or option in the settings to launch the Task Manager conveniently. This is why it is launched in different ways for different models and makes of Android smartphones. In many phones, you have to long-tap the home button (the middle button) when you are at the home screen to launch the Task Manager. Some phones require you to go to home screen and then quickly tap twice on the home button. In other phones, you have to press the menu button (the left button of the three buttons given at the bottom of the screen), when you are at the home screen to launch the Task Manager. If none of these methods work for you, then perhaps you will have to ask your phone manufacturer for specific instructions.
When the Task Manager is shown, it will look akin to the Alt+Tab switcher screen of Windows – displaying all the tasks running along with their thumbnails. You can actually scroll up and down (or left and right) and tap on any of these thumbnails to quickly switch to that app.
If you want to kill any of these apps, then you can long-tap on the thumbnail of that app for a few seconds until a small menu appears. You can select Remove from list option from this menu to close that app. There is also another option labeled App Info that will show some information about that app.
One another and much quicker way of killing an app is to drag the app off from the list. If you are holding the phone in horizontal position, then you can drag the target app either up or down to take it off the Task Manager list. In case you are holding the smartphone in the vertical position, then you can drag the target app left or right off from the Task Manager.
Conclusion: You do not really need a third party task manager app from Google Play Store, simple because Android has a simple and powerful Task Manager built inside it. You can use this Task Manager to see which apps are running in the background (or foreground) and to stop any one of them at your will.