A bit more detail, as promised:
App will consist of a home page with links to the most common functions of Talk - Threads I'm, Threads I'm Watch, Topic List, Active Convos. There will also be some space for some some user-selected topics. You will be able to browse the topic list a category at a time.
The threads themselves will be displayed in a similar way to the web version now. There will be no columns, but there will be a couple of ads in the run of the page.
Posting will be as now, but somewhat simplified - the instructions for use of emoticons won't be there for example, or at least not permanently but might be available from a link. You will be able to subscribe to threads that interest you. There won't be functions to exclude threads or topics, nor will some of the customise options be there - there will only be a single colour scheme (based on Mumsnet New), you won't be able to say how many posts per page, etc. but you will be able to choose if you read up or down the thread chronology.
There will probably be a search function though possibly not in the first version.
Hope that makes sense - we are trying to balance simplicity with functionality (and speed of development)