What does an app that genuinely works for your business cost?

This is the smallest option: pages, a contact form and an admin screen where you change texts and photos yourself. There is little logic in it, so the work sits mostly in the design and in filling it.

Here the work sits in what the application does: entering, looking up, approving, reporting. Every screen is a piece of your process, and we have to get that process clear together first.

An app costs more than the same thing in a browser, and not only because of the building. You need a developer account with Apple and with Google. The app has to be signed and made ready for release. There has to be a store page with screenshots, a description and a privacy statement. Then Apple and Google check the app before it appears in the store. Every later update goes through that check again. That work is accounted for in the estimate.

Two shells on one system. The data and the logic are shared, but the screens get built twice and tested twice. And the app has to go through the stores: a developer account with Apple and with Google, signing and preparing a release build, a store page with screenshots and a privacy statement, and a check before anyone can download it. Every update goes through that check again. That is what the extra fixed amount and the extra days pay for.

A perfectly good answer at this stage. We reckon with an average web application. In a first conversation this is usually clear within half an hour.