Mozilla is developing Firefox browser for iOS with Gecko engine instead of WebKit.

Mozilla is working on a Firefox browser for iOS based on the Gecko engine instead of WebKit. Earlier it became known that Google's Chromium team is developing a browser for iOS based on Blink. Mozilla's GitHub repository found  code for an iOS version of the Firefox browser mentioning the GeckoView wrapper for rendering in the Gecko engine.

Apple's rules currently forbid the use of any third-party engine for browsers other than the proprietary WebKit engine. Last week, Chrome for iOS bug reports found mention of the Blink engine, which also can't be used to develop iOS browsers