When Should You Build a Custom App for Your Business?

Custom apps, mobile or web, are expensive. A serious build runs £80k to £500k and 3 to 9 months. Done right, they create a defensible commercial moat. Done wrong, they are the most expensive piece of software your business will ever throw away. Here is a framework for deciding which side you are on.

Start with the build-versus-buy question

Before you spec a custom app, list every SaaS product that does even 70% of what you need. The cost of integrating three pieces of off-the-shelf software is almost always lower than building one custom app. The exception is when the 30% you cannot get off-the-shelf is the part that drives your competitive advantage.

The three signals that justify custom

Custom app development pays off when one of three things is true. First, the workflow is your business. If you sell logistics, your logistics software is the product, not a tool. Second, the unit economics break: your SaaS bill at scale exceeds the amortised cost of a custom build over three years. Third, the integration burden is unsustainable. When you have eight tools, four spreadsheets and a part-time ops person stitching them together, custom is cheaper than the alternative.

Mobile versus web

Default to web unless your product genuinely needs the phone: camera, GPS, push notifications, offline-first, biometrics, in-pocket frequency. A web app reaches every device, is cheaper to maintain, and bypasses App Store gatekeeping. Mobile is worth the extra cost when the use case is mobile-native.

How to scope it

Scope the smallest version of the app that proves the unit economics. Two months. One workflow. One user role. Ship it, measure it, then expand. The teams that fail at custom apps are the ones that try to ship version 3.0 as version 1.0.

WOOWEB DIGITAL ships custom web and mobile apps from our Mayfair London studio. Discovery is paid, scoped to two weeks, and ends with a fixed-price proposal. Email hello@wooweb.digital to start the conversation.