https://www.theverge.com/2018/5/1/17307264/google-app-top-level-domain-name

Google is now letting people make sites ending in .app, releasing its monopoly on the top-level domain after three years. Google acquired the top-level domain .app in 2015, after shelling out just $25 million for the honor. Top-level domains are the last part of a domain name, like .com or .org.

.app was a highly desired name by website makers, given the association with apps. As Google puts it in its press release, “Even if you spend your days working in the world of mobile apps, you can still benefit from a home on the web.”