28 May 2020
UPDATE (May 21st, 2020):
OnePlus, Realme, Meizu, and Black Shark have become the latest Android phone makers to join the cross-platform file sharing alliance. It means users of phones from these brands along with existing members will be able to share files with each other without having to rely on a third-party app. These new OEMs have only become a member at the moment and we do not know when they will start releasing phones compatible with the protocol.
UPDATE (January 2nd, 2020):
Vivo has officially confirmed that its cross-platform file sharing system will become available globally starting February 2020. It is working on the system in collaboration with Xiaomi and Oppo for the past four months. It will allow users of these OEM devices to transfer files wirelessly and without requiring to install any dedicated app.
The system is based on the peer-to-peer transfer protocol and will work with "just one click". Vivo says users will have to enable WiFi and Bluetooth connections to use the feature. It will also provide an option within the system settings. Since it relies on WiFi P2P technology, users will be able to use WiFi internet uninterrupted even when sharing files.
Original (August 19th, 2019)
Xiaomi, Oppo, and Vivo have come together to form an alliance with the goal of providing a cross-brand file transfer service. The announcement regarding the alliance was made by respective official Weibo accounts meant for MIUI, ColorOS, and Funtouch OS. It is essentially a peer-to-peer file transfer protocol similar to Apple's AirDrop functionality.
In its current state, the protocol will work on smartphones from Xiaomi, Oppo, and Vivo and that too without requiring any new app installation. It will be a system-level service that will work natively as long as users have a compatible smartphone. It is said to be capable of transferring different file formats like videos, audios, photos, and documents. The transfer speed is claimed to be up to 20MB/s which is quite fast.
The aim of the alliance is to solve the problem where Android users have to go for a common third-party app for sharing files. With a native offering, it should be like using Bluetooth but much faster and more efficient. Another good thing is that alliance is open for any other Android OEM to join. It means we could see other players like Huawei/Honor and Samsung becoming a member which would truly benefit a huge number of Android users worldwide.
As for the availability, an open beta is expected to become available by the end of August which means within about 10 days from today. The public release should happen sooner than later but will also depend on the success of the open beta.