One of the things I love about Android is the way it allows fantastic customization of its user interface, even without root or other major modifications. Take App Swap for example: this handy little app drawer replacement can launch either from a standard shortcut on your launcher (or alternative methods like SwipePad) or it can replace the default Google Now swipe-up-from-the-home-button gesture.
The latest update to this tool adds an even more useful feature: Quick Swipe. This allows users to swipe left or right from the pop-up app drawer to instantly go to the apps of their choice. Essentially it's an even faster way to get to your two most-frequented apps. If you spring for the very reasonable $1.99 in-app purchase upgrade, you can add swipe zones on the top and bottom, allowing three apps to be launched with Quick Swipe actions on either side, for six in total. If you feel like getting really fancy, these zones can also be assigned to opening widgets outside of the launcher. The GIF below, from the developer's Google+ account, shows these six swipe zones in action.
The other neat part of App Swap is the T9 function. Tap the dialer icon beneath the app drawer and you can use your old-school T9 texting skills to quickly search through the apps on the screen - very handy for someone who keeps hundreds of apps on their device. You can also use a standard keyboard for searching if the fancy takes you that way. An impressive amount of customization settings allows users to further tailor the app to their tastes. Check it out if you're looking for a unique and fast way to get to your apps from anywhere in Android.