The wrong reason to build an app
“Our competitors have one” is the most common reason, and the most expensive. An app takes an upfront budget, but above all a permanent upkeep budget: two operating systems updating twice a year, two app stores to satisfy, and users who have to agree to update.
Question 1: do your users come back weekly?
An app is justified by frequency. A bank, a gym, a delivery service: yes. A brochure site visited once before calling: no. Below one visit a week, the icon ends up deleted.
Question 2: do you need the phone's hardware?
Continuous camera use, Bluetooth, background location, sensor readings, working with no network. If the answer is no, the mobile browser now handles almost everything else.
Question 3: are notifications central to your service?
Push notifications remain the strongest argument. But beware: an unwanted notification is the number-one cause of uninstalls.
Question 4: can you maintain the app for three years?
An abandoned app is worse than no app: it eventually gets pulled from the stores, and the negative reviews stay. Budget 15–20% of the initial cost per year to keep it alive.
Our default recommendation
Start with an excellent mobile site. If it's fast and well designed, it covers the vast majority of cases. Launch the app when you can prove, with your own numbers, that your users come back often enough to keep it.