For change status quickly and automatically on menubar.
Open the app then you can sign in with Slack on preference.
This app use Sign in with Slack. Please check your Team settings. You have to enable Sign in with Slack.
When Approved Apps enabled, You have to waiting for approval by Team manager to install app.
When Only allow apps from the Slack App Directory enabled, I'm Sorry, You can't install tha app 😢
Unfortunately, the app does not distributed app 🙇