userProfileLookup is not supported in Nintex Mobile Apps
Currently the userProfileLookup() runtime function is not supported in Nintex Mobile Apps.
Please add this functionality for Nintex Mobile Apps.
Ref number [ ref:00D90q6Cb.5009028Rb9T:ref ]
I am pleased to confirm the UserProfileLookup function is available in New Responsive Forms for Office365.
Matthew Kwan commented
FYI, userProfileLookup function is supported on O365 new responsive form in Nintex Mobile Apps.