From the website:
The goal of the site is to create a free and competitive real time alert tool for the U.S. judicial system.
At present, the site has daily information regarding all precedential opinions issued by the 13 federal circuit courts and the Supreme Court of the United States. Each day, we also have the non-precedential opinions from all of the Circuit courts except the D.C. Circuit. This means that by 5:10pm PST, the database will be updated with the opinions of the day, with custom alerts going out shortly thereafter.