One of the most talked about features in the latest version of Android (Marshmallow) and also in the upcoming version Android N is the ability to switch through the running apps with ease. These newer versions of Android are perhaps designed keeping the multi-tasking features in mind. But if you are running a relatively older version of Android (Lollipop or KitKat) then you can install the Swiftly Switch app to quickly switch through the apps running in the background.
After you have installed the Swiftly Switch app in Android, you are asked to make two system settings – activating the access to usage stats feature for the app so that it can find out which apps you have been running (& consequently provide you with a way to switch to them) and enabling the accessibility options for the phone. Once this is done, you have to enable Edge 1 or Edge 2 or both. These edges are the regions where if you touch, a circular menu for switching through the apps is displayed. The Edge 1 region is by default near the center-right-edge of your phone’s screen and the Edge 2 is available only in the paid pro version.
You can customize the various settings related to these edges like the mode, position, sensitivity, length, offset, and the circle size. Now when you touch the screen in the specified region of the screen (as defined by Edge 1 or Edge 2), you are shown a circular menu containing your recently launched apps. You can tap on these shortcuts to easily and quickly switch to those apps.
If you want some apps to be always displayed in the menu, then you can add them to the favorites apps list. Similarly, if you do not want some apps to be ever displayed in the menu (even if they have been recently used), then you can add them to the blacklist.
You can get the Swiftly Switch app for Android from https://play.google.com/store/apps/details?id=org.de_studio.recentappswitcher.trial.