It turns out that it is possible to update the firmware of the microcontroller through a web browser without additional software, using the WebSerial API Web Serial API - Web APIs | MDN.
The demo page allows you to upload to ESPboy applications and games as proof of technology ESPboy AppStore Demo
Many thanks to Steph for this great tool!

Discussions
Become a Hackaday.io Member
Create an account to leave a comment. Already have an account? Log In.
This is super helpful (and a neat use of the browser) - thanks, Steph!
Are you sure? yes | no