Key-combination support could be improved
I use byobu (a fancy front end to screen/tmux) on most of my servers. It's great, but relies on a lot of key combinations like shift+arrow, shift+fX, alt+fX, etc. So far I haven't found any iOS ssh clients that seem to handle this properly (I can toggle shift, then press fX on your keyboard extension, but it only seems to send an unmodified fX. Ditto with alt and ctrl, with fX and arrows). If you could make this work it would be a huge win for me.