Better KQB Scoreboard helps casters keep track of scores and display them beautifully within OBS. It is primarily targeted at IGL match casters, but will be adding support for custom matches as well. It allows you to directly import team data (teams, standings, avatars, etc.) directly from IGL so there is no room for error when setting up your stream. It will prompt you to record map wins and will tally the results for you and they will be displayed properly within the widget. Thus allowing you to focus on streaming and let the widget handle the legwork for you.
KQB Scoreboard was written in Go and provides a browser widget interface for use with OBS.