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Product · Fintech · My own app

Mortgage Calculator UK

Eight years in, the data said half my users weren’t who I built it for. The redesign turned that discovery into revenue.

Mortgage Calculator UK
Role

Designer, owner, product lead

Scope

Full redesign and subscription tier

New users

6,000+ a month

Platform

iOS

Mortgage Calculator UK

The problem

Ten thousand people a day were using a calculator you use once.

This is my own app, live since 2014 and taking over 6,000 new users a month. Eight years and one redesign in, the Firebase data showed something that made no sense: more than 10,000 people were opening it daily.

A mortgage calculator is a once-or-twice tool. You check what you can borrow at the start of your search and you don’t come back. Daily use meant a group of users I had never designed for was quietly living in the app, and I had no idea who they were.

Mortgage Calculator UK screens
Mortgage Calculator UK screens

Firebase data, then an in-app feedback screen: how a decade-old assumption got corrected.

What I did

Three decisions the product hangs on.

01

Asked the users instead of guessing

I put a feedback screen inside the live app rather than theorising. The answer came back quickly: mortgage brokers and estate agents were using it all day as a working tool in front of clients. Nothing in eight years of assumptions would have got me there.

02

Split the product into two users, not one

Rather than compromise the design between casual and professional use, I designed for both explicitly. Regular users got their pain points resolved and nothing else added. Business users got a separate surface built for repeat, in-front-of-a-client use.

03

Turned the discovery into a subscription

The professional tier is the commercial answer. It adds extra calculators and tools that make a broker’s day faster, behind a subscription. This monetises the group that was already there and getting the most value, without putting a paywall in front of a first-time home buyer.

Mortgage Calculator UK screen
Mortgage Calculator UK screen
Mortgage Calculator UK screen
Mortgage Calculator UK screen
Mortgage Calculator UK screen
Mortgage Calculator UK screen

Two products in one app: the free consumer calculator and the subscription broker toolset.

Outcome

What it did once it shipped.

New users a month6,000+
Daily active users at redesign10,000+
Lifetime downloads200,000+

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