Hey there,
My name is yousef hamza, I’m the developer working on OpenMRS iOS Client.
I’m right now just testing the implementation of xforms on the client, but some forms give error submitting the form ‘the exact same when submitting the form from the web interface’ and that blocks me from continuing my testing.
Here’s the stack trace: http://pastebin.com/JB2BzEiH
So any help is appreciated tell 
You can try it urself here: http://52.27.34.83:8080/openmrs/module/xforms/formEntry.form?personId=4&patientId=4&returnUrl=&formId=6&target=xformentry
I would appreciate your input @dkayiwa @darius
§Yousef