Slack (for Android)

The Slack Android app has a similar interface to the Slack website and desktop apps. For example, it has an Activity view that shows interactions on Slack that involve you or channels you follow.

You can sign into multiple Slack accounts from one Android app and easily switch among them from this left side collapsible pane.

Notifications, and the ability to customize them, are a big deal in Slack, especially in the mobile apps. You can change the intensity of vibration, the audio alert tone, and even keywords so you can know when someone is having a conversation about topics that are important to you.

Channels and direct messages appear in a collapsible left pane in the Slack Android app. Threads with unread posts appear in bold.

When you paste a link into a Slack message, Slack sends a decent preview of what's on the link. The previews provide context, making communication not only easier but also better.

Another important function for the Slack mobile app specifically is the ability to snooze notifications for a period of time, letting you concentrate on work, take a nap, or do some other activity without interruption.