Lots of people are struggling to get this App to work most are seeing
'Uh oh! Either the WHS Mobile domain is incorrect or the domain cannot be contacted'
I found this post by Mike Burrows in a blog on compugeek and it worked like a charm for me so I thought I'd share it
Was just struggling with the same app connection failure on iOS4 as a number have mentioned.
The magic worked for me when:
I manually changed the port number in the settings (as mentioned) to a bogus port (eg. 11111)
went back to settings main page
went back to home screen
brought up the multi-tasking apps and killed settings
Started WMSMobile, gave it 30 seconds as it obviously is failing to connect..
Go Back to home screen
brought up the multi-tasking apps and killed WHSMobile
Go back to WHSMobile settings and changed port back to the usual 8169
Go back to main settings
brought up the multi-tasking apps and killed Settings
Ran WHSMobile and it worked...
Yes, this is likely overkill but this was the only combination that worked for me
Hope this helps some others use this great app!