Build me an app for my event

Hello we have a big conference coming up and we have 150 guests plus. We have MPs and businesses as well as landlords and tenants so a real mix of back grounds. We are a tenancy advocacy group and have secured some funding for this event and possible furure events. What we really like is the idea of an app breaking the fourth wall of communication at the event so that the delegates xan ask questions directly to keynote speakers. Also that people could use it to network, be reminded of our event or future events and access services, we want it to be as useful as possible. We'd be having regular events on smaller scales too around the regions.

Id really like to know more anouy what services can be sourced and what can be done by the team we have already. It would be interesting to learn what a full service costs and what a skeleton service costs. If you want any more information and might be interested wed love to hear from you. ?