For most companies, a website is enough, and it is the thing to build first. An app is worth its ongoing cost only when there is a repeat action that a website does badly.
If there is no clear thing an app would do better than your site on a phone, you do not need one yet. If customers or staff do the same task with you every week and it needs a camera, offline use, a login they keep, or a notification, an app will pay for itself. Build the website first either way: an app for a company nobody can find is an app nobody installs.
A web app that installs to the home screen and works like an app without an app store. For forms, lists, lookups, bookings and dashboards it does the job at a fraction of the cost of building for iPhone and Android separately, and it changes as fast as a website. It is the right first step for most internal tools and for most customer-facing apps that do not need the phone's hardware.
Building the app before the audience exists. The company has a good idea, spends the budget on the app, launches it, and finds that people who use a business twice a year do not install its app. Meanwhile the website that would have brought those people in was never built. Earn the repeat customer first; then build them the app, if they still ask for it.
If the website side is the gap, read business websites. If you can name the repeat task and the people who do it, read business apps and then what drives the cost. If you are still unsure, describe the task in an email and you will get an honest answer, including "not yet".
Yes, and the order matters: website first, because it is how people find you, then an app for the repeat task once you know what it is. Building both at once doubles the scope before either has proven itself.
Not because they have one. Ask what their customers do in it every week. If you cannot name that action, their app is probably a cost to them, not an advantage. If you can, and your customers do the same thing, that is a real reason.
To the person using it, yes: it opens from the home screen, fills the screen, and can work with a poor connection. What it cannot do is use every phone feature or sit in the app store. For most business tasks neither matters.
A short message is enough to start: what the company does, what the website or app has to do for it, and when you need it. You will get a reply from a person.
