GroupBlaster is a browser-based tool for scheduling posts to Facebook groups. It allows users to write a post once, select the groups they want to publish to, and define a schedule for the posts to be distributed. The tool is designed for individuals and organizations that manage multiple Facebook groups and want to automate the posting process. Posts are organized into campaigns, each containing its own content, target groups, and schedule. Users can set posting cadences to once, daily, weekly, or monthly. The tool supports spintax for generating text variations across different groups. It provides sequential publishing with live progress indicators and maintains a history of published posts with links back to them. The tool operates as a browser extension compatible with Chrome, Edge, and Brave. It requires a Google account for sign in, and user data is stored locally in the browser. A free tier is available, offering five campaigns and ten posts per month, with an upgrade option for unlimited posting. This setup is suited for users who regularly publish content across multiple Facebook groups and want to centralize the distribution workflow.