Maximiliano Firtman is an Argentinian developer and one of the most cited independent voices on the mobile and Progressive Web App (PWA) sides of front-end engineering. He is the author of multiple books on mobile web development — including High Performance Mobile Web (O'Reilly) — and a long-running Frontend Masters instructor on the PWA, mobile-web, and modern web-platform tracks.
His course catalog covers PWAs in depth (service workers, the Cache API, push notifications, the install / standalone-app patterns), mobile-web performance, the modern web-platform APIs that have replaced what used to require native apps, JavaScript / TypeScript for working developers, and the broader mobile-and-web boundary that most pure-mobile or pure-web courses don't address.
The CourseFlix listing under this source carries 5 Maximiliano Firtman courses spanning that range. Material is paid; Max's courses are primarily distributed through Frontend Masters on the original platform.