Can players play Minecraft on Android devices and Xbox One together?

Thanks to Minecraft's "Better Together" update, players hoping to play the world-building game together can do so, they'll just need to make sure they're all on Minecraft's Bedrock version.

Minecraft's Java edition, while still allowing cross-platform play, only allows it for PC, Mac and Linux. For those hoping to play with others on any platform, including consoles and Android/iOS devices, players will need to play the Bedrock edition. Bedrock edition is slightly different from Java in a number of mechanical ways due to being made uniform for most platforms, but it can still be incredibly enjoyable, especially with friends across the platform divide.

Minecraft: How to play cross-platform multiplayer in Bedrock version.

In order for Minecraft players to enjoy multiplayer together between platforms on Bedrock edition, they'll need to set up a few things. Compared to setting up a server or Local Area Network or buying a Minecraft realm on Java, the process is significantly easier. All it will take is a few button presses and before they know it, players will be able to enjoy a Minecraft world with their friends.

At Minecraft's main menu, players will need to log in to their Microsoft account. Xbox One players will already be logged into one on launch, but other platforms will need to sign in to the account before they continue. Console players will also need to have an active subscription to whichever service they are currently using, such as Xbox Live or Nintendo Switch Online.
Once signed in, players will want to load or create a new Minecraft world. Once it has loaded in adequately, the player will need to open their pause menu.
On the far right of the pause menu there should be an "invite to game" button. By pressing that, players will be given a number of options to invite players to the game, but the button they will want to select is labeled "find cross-platform friends."
Players will then want to find their friends via their Minecraft ID/Gamertag, and select "add friend."
Once friends have been added to a player's friends list, they will be seen when available under "online friends." Players will want to check the box by their Minecraft ID and then press the button "send invite."
Once the player has received the invite, they can enter the world at their discretion, and the players can play together to their heart's content.

Keep in mind that not all Minecraft worlds are cross-platform due to different content releases in Bedrock edition that are console specific. For example, the "Mario Mash-Up" world will only work for Switch users to play with other Switch users, as the content is exclusive to Nintendo.