Note that both versions of the beta app now support logging in, creating accounts (with captcha), and basic wikitext editing.
iOS version now includes optional edit summaries, with an experimental 'canned summary' feature where you can select some common notes.
There are also updated localizations from
translatewiki.net -- please give a shout if there are obvious problems with the UI not matching the phone's system language; it's our first build since the new updates went in.
Android edit summaries didn't quite make it through review yet, but should be available in a beta update in a couple days.