Android 5.1 vs Android M - App Tray
With Android M the application tray or drawer has been changed yet again. It's different on phones than it is on tablets, but you'll immediately see the changes in our screenshot. Instead of flipping through horizontal pages Google's gone back to one huge vertical scrolling list.
They're still listed aplhabetically but there's letters before each section, it's all broke up with gaps (which looks odd) but the best part is the top of the application tray.
You'll now see four of the most recently opened apps, as well as a search bar right inside the app tray. Meaning you can instantly find one of the last four apps you opened, or hit the search button to type (or use your voice) to search for and open an app. The look is something we'll have to get used to, but it's a great change and makes using Android even easier.