Want to build custom apps and integrate them into Teams? Head over to the Microsoft Teams developer platform for documentation and step-by-step directions.
For example, you can configure a bot to send your team a daily weather report, build a tab to host an internal tool, or set up a connector to give you updates on an existing data feed.
Once you've created a custom app, go to the team name where you want to add it and click More options > Manage team. On the Apps tab, click Upload a custom app in the bottom right corner.