Streamlabs

Streamlabs Desktop, once called Streamlabs OBS, runs on the same open source engine as OBS Studio and adds the parts most streamers end up bolting on anyway: installable overlay themes, an alert box for follows and tips, chat in the app, and a hosted tipping page. Logitech owns it, and the paid tier adds multistreaming to several platforms at once.

Weigh a couple of things before switching. It asks more of the machine than plain OBS at identical settings, which matters when you are gaming and streaming on one PC. And the alert widgets work as browser sources inside plain OBS, so you can take the alerts without taking the app.