Flow (web browser)
Flow is a web browser with a proprietary browser engine. Its JavaScript engine is the SpiderMonkey component of Firefox.

Flow is developed by the Ekioh company, which has made simpler browsers for set-top boxes and other embedded systems.

Flow is a recent entrant to the browser market. The first beta was in December 2020. Ekioh is focusing on its use in embedded systems, including a beta version for the Raspberry Pi.

References 

Web browsers
POSIX web browsers
Layout engines