Messenger

Messenger is Meta’s standalone chat app, split out from the Facebook app years ago. If your contacts are on Facebook, this is how you reach them; that is essentially the whole case for it.

Encryption is on, but check your older threads

Meta completed the rollout of end-to-end encryption by default for personal chats. The detail that catches people out is that it applies going forward — older conversations may still be stored unencrypted unless they were migrated, and some contexts (community chats, some group types) work differently.

If a conversation matters, open it and confirm it shows as encrypted rather than assuming.

Resource use

Messenger has a long-standing reputation for battery and storage consumption, and it is mostly deserved. Two settings help materially:

• Turn off automatic media downloads. Cached photos and video are usually the bulk of the storage the app accumulates.
• Chat heads and background activity can be restricted per-app in Android’s battery settings without breaking notifications.

The lighter option

Messenger Lite exists in some regions and does the core job at a fraction of the size. Availability varies by market, and Meta has withdrawn it in several. Worth checking before installing the full client on a low-end device.