Looking for beacon to broadcast a custom message to devices

I am new to the beacon world and had a question on creating an app or programming a beacon. What I essentially am looking for is to have a beacon send a message to a user once he/she gets into the range of that beacon. Will I need a custom app or will Chrome be able to detect using the Eddystone protocol and send a pop up notification on that device?

An example for what I am talking about would be: I have a beacon set up at a certain location. A user walks within the range of that beacon and a message pops up on the users device letting them know that he/she is at a specific location. The goal is to have these notifications work both on iOS devices and Android devices.

Thank you for your help!