If the organizers of your event have enabled the Help Desk in the Info Booth section, you can use that to email them. Alternatively, you can always contact us!
If you’re experiencing a technical issue, it is always a good idea to include information that helps us to understand it, including your device (e.g. iPhone), operating system (e.g. iOS9), and browser (e.g. Safari), as well as any steps you took right before you experienced the issue. If you're not sure what your device and browser information is, you can visit https://aboutmybrowser.com/, which will provide you with a link to send us so we can take a look for you.
If your question has to do with the event itself (e.g. "When is the keynote speaker giving her talk?" or "Where is lunch being served?"), your best bet is to contact the event organizer directly. EventMobi Support would just defer to them to answer questions like that anyway.