For Android users seeking a privacy-focused browser, Privacy Guides recommends Mull:
Mull is a privacy oriented and deblobbed Android browser based on Firefox. Compared to Firefox, it offers much greater fingerprinting protection out of the box, and disables JavaScript Just-in-Time (JIT) compilation for enhanced security. It also removes all proprietary elements from Firefox, such as replacing Google Play Services references.
Mull enables many features upstreamed by the Tor uplift project using preferences from Arkenfox. Proprietary blobs are removed from Mozilla’s code using the scripts developed for Fennec F-Droid.
Maybe on android but not on iOS
Plus if you don’t have any next tab the swipe creates a new tab instead
Unless you use the synchronization features of Firefox, I think it would be best to use safari on IOS.
At least until they bring their own engine to the OS.
My reasoning: None offer content blocking, you get better fingerprinting protection with safari and you have one less application.
Safari offers ad blocking on iOS. You just have to get your extensions through the App Store. But other browsers don’t (yet).