Hey raf,
as it has been for the Mac version before the groups button that is shown in landscape mode is way too small. For group names that are longer than approximately 5 characters the name just overflows the other buttons causing bad readability. I guess there is no nice way to solve this problem as for non-retina iPhones there is simply not enough space for all those buttons. Speaking for myself I wouldn't like to miss the groups button as I use very often, a lot more than the protocol buttons. I suggest moving the protocol buttons in a button group (like the groups button group) too.