SF OS X

Android. That's the operating system which most probably runs on your mobile phone.
While this is the very common system to have nowadays, it's matured enough throughout the years and built very rich ecosystem of applications, there are a few things which I don't like on it.

The basic idea is, that if you buy something, you should own it. You should be able to disassemble it and modify it, to adjust it to your needs and most noticeably: you should be in full control of your device.

Hide Tab Bar in Firefox 57+

Finally I've found a way to hide tabs from Firefox.
I use Tree Style Tabs addons and don't need native tabs.

So here is how you can do it: