Since long, Android users have been craving for the facility to be able to move their apps and app data between their phone’s internal and external storage or the miroSD card. Sadly, Google didn’t seem to care much about it as after Nexus One, none of their Nexus phones and Tablets have had a microSD card slot. Now finally, Google has capitulated to popular demand and the latest Android M comes with this facility.

Google introduced Android M with several new features at its I/O conference this year and the feature of “Adoptable Storage Devices” is one of them. Actually, it is the name given by Google to removable external storage or microSD cards because they are adopted to become a part of the mobile device’s internal storage. The company did not elaborate much on this new feature at the I/O but references to this feature are found in Android M developer preview documentation. According to that, users will be able to move apps and app data to the external storage only if it is specifically allowed by the app developer in the app.

Although earlier Android versions didn’t offer this feature, certain smartphone manufacturers added this feature on their own. But now Android M will officially have the microSD card support built into it. In fact Android M will now support several features such as custom quick settings, support for fingerprint reader, themes etc. which the OEMs were providing in their products on their own.

According to the official documentation:

“With this preview, users can adopt external storage devices such as SD cards. Adopting an external storage device encrypts and formats the device to behave like internal storage. This feature allows users to move both apps and private data of those apps between storage devices.”  

Here, the external device gets encrypted, so another device may not be able to read the data moved to it. Also, it is possible that the app moved to the microSD card may not work when the card is pulled out of the device.

The Adoptable Storage Devices feature of Android M will also apply to external USB sticks as this OS will have built-in USB OTG support. This feature will be useful for Android TVs and gaming consoles.