Mainstream desktop browsers end up overloading the horizontal axis as a way of switching tabs. In contrast, mobile browsers use vertical space for this purpose.
Vertical switching aligns with long-standing use of vertical ordering in catalogues and as a natural way of arranging todo items.
The bottom of a page is a natural place to provide easy access to the next trail, which is conveniently accessed by scrolling past the end of the page.
Vertical scales better
The average person tends to have either less than eight tabs open, or to add tabs without organization until declaring “tab bankruptcy” and starting fresh.
I've prototyped utilizing gyroscope to provide extended context.