Android 5.0 introduces a redesigned Overview space (formerly called Recents) that’s more versatile and useful for multitasking.
New APIs allow you to show separate activities in your app as individual documents alongside other recent screens.
You can take advantage of concurrent documents to provide users instant access to more of your content or services. For example, you might use concurrent documents to represent files in a productivity app, player matches in a game, or chats in a messaging app.
Android 5.0 adds new APIs that allow apps to perform concurrent operations with Bluetooth Low Energy (BLE), allowing both scanning (central mode) and advertising (peripheral mode).
New multi-networking features allow apps to query available networks for available features such as whether they are Wi-Fi, cellular, metered, or provide certain network features. Then the app can request a connection and respond to connectivity loss or other network changes.
NFC APIs now allow apps to register an NFC application ID (AID) dynamically. They can also set the preferred card emulation service per active service and create an NDEF record containing UTF-8 text data.