I know there is already one nice open source app called BTC Map for that, so is there any advantage of using Envoy app for this purpose?
As a frequent traveler I could support the using Envoy app for finding the local crypto ATMs as such feature eliminates the need of having extra apps on your mobile. The less apps on mobile the more safer it is.
As to partnering with RAMP, probably those who use this service will appreciate this, but I prefer to buy/sell BTC on decentralized p2p exchanges particularly on bisq which is my favorite.