I've been involved in running events on and off since 2002. I created Eventfuel.io to improve the use of technology at events to make everyone's experiences better.
I have been on both sides of the event app selling process. There are many one size fits all approaches that rarely work. I know many solutions in the market. However if I think Eventfuel.io is a good fit with what you are looking for I may suggest it.
I've been using Beacon technology at events since 2013. I know it's weaknesses and strengths and when it is appropriate and how you need to provide it transparently to your attendees to get them to agree to it.