If you go to the Profile, you can post from there! I'm sorry - I chose Mobility, because it's supposed to be better on phones and I was trying to make it more accessible, but it apparently won't show the navigation bar on this layout!

So, I am going to find out and change it to something less inconvenient for everyone else asap, but in the meantime: go to the profile page & in the top right hand corner on the little list of actions you can press the 'post' option. (You can also post to comms from your journal by selecting 'historium' instead of scripsi, but I tend to avoid doing that as it's very easy to choose the wrong one on the list!!)