A new staff member cannot log into the app and sees an error to add the ServiceM8 Phone add-on. Why?

Please note there two mobile apps on the iOS App Store, the core ‘ServiceM8’ job management app, and the optional ‘ServiceM8 Phone’ app, the latter being part of ServiceM8’s optional cloud phone system. It sounds like your staff member may have installed the ‘ServiceM8 Phone’ app from the iOS App Store by accident, when in fact they need to install the ‘ServiceM8’ app.