Is it App must and should for beacons?

Is App must for the connectivity of beacons or bluetooth enabled device is enough ?
And how can this beacons be used in restaurants for menu info and other push notification.
please help me with the information for integration in restaurants and other retail store…

An app is a must to detect beacons, yes.

I recommend taking a look at our Getting started with Estimote, beacons, and microlocation guide, it should give you a solid base understanding of how beacons work and how you can use them.