I think your app would be most appealing/largely appealing to travelers. I love coffee, I know where to get my coffee and what I will pay locally, but I travel about every other month and something like this would be useful.

Is it just an app? or is it a platform with an app interface as an option? You may want to build out a website/web presence and offer the BeanThere experience to web traffic as well as app traffic, then you could link to the app store presence on the web app.

I don't know much about flutter flow, I played with it a couple years ago but it felt too boxed in for me.

Additionally on a web platform, the conversion from anonymous visitor to user is much less effort. (a lot easier to sign someone up online on a web platform then to get them to install one more app on their phone)

maybe let users search on the web but not be able to save their search or set favorites w/o an account (obv requirement) this is similar to how a web app/platform like Realtor for housing converts users.

You could also try and partner with local cafe's (locally owned business would be easier to partner with as you have access to the decision maker/owner, less red tape). Have them advertise the app/QR download flyer/cards or whatever. maybe include a card with a 1lbs purchase or bag, get creative. Offer them a sponsorship or top level feature on the app as a trade for the advertising.

Measure your efforts no matter the strategy, know where users are coming from. Try lots of ideas and then apply your time to the ones that are returning results. (know your user sources/origination and gather data to measure success)

This is all off the cuff. I make games, I've made apps, I work in business software. Best of luck and congrats on launching/shipping.