Numerical: The Calculator without Equal

A novel approach to app marketing

In 2014 I was teaching myself iOS application development and design. One of my first projects was to create a simple calculator. Over time this idea developed into a minimalist calculator with a simple hook: there is no equals button. I developed the app in public, chronicled the development on a podcast, and eventually released it with some simple design-centric marketing, and it became a surprise success with 500k lifetime downloads and featured on dozens of tech blogs.

A Career Pivot

I completed a bachelors in film studies at Flinders University in 2010, and began working in the Australian film and TV industry. I found work and was relatively successful in this enterprise, but after a few years I began to get bored and started to explore other career aspirations. The one which stuck was iOS app development and design. I started reading books and completing online courses, and stumbled across a novel little concept - a calculator app that evaluated your answer as you typed.

This was a relatively unique concept at the time, and iOS app design was still stuck in it’s skeuomorphic design metaphor, so I wanted to go against that trend and make a calculator that was unique, delightful, and minimalistic.

I was the co-host of a successful tech podcast at the time, The Menu Bar, where me and my best friend would discuss design, interview bloggers and developers, and foster a small Apple-focused community of like-minded geeks. As I started developing Numerical I would talk about the trials, difficulties, and it became an ongoing project. This resulted in it being a public project, where I received a lot of advice and feedback.

Iterative Development

The apps development was slow and iterative. As I sharpened my development skills I rewrote and refactored the codebase. Through trial and error I realized that the reason calculators have an equals button is that it allows the user to control their orders of operation, such that they get an answer calculated step by step. To adhere to BODMAS order of evaluation (you remember grade school math) I developed a smart bracket system that would automatically add opening and closing brackets as the user typed.

The interface steadily became more colorful and dynamic and I eventually joined forces with a design friend, Alex Vanderzon, and we designed the crisp pink color palette and layout that eventually shipped. I added sound effects for buttons taps, and micro-animations for various input and state changes, such as swiping to undo. This iterative process resulted in a design that was sharp, clean, and strikingly modern for 2014.

Marketing

My study of film, storytelling, and motion design put me in a fortunate position when it came to marketing and releasing Numerical. I had made plenty of press and marketing kits to promote short films and other projects I worked on, so I put together a detailed and delightful marketing kit and sent it to every tech and design blog that I could think of.

I created some short videos to demonstrate the simplicity, ease, and delight of using the app, all centering on the concept of “No equals button”. Some of these videos achieved minor viral-success in design communities and forums.

Release and Legacy

Numerical: The Calculator without Equal was released and became a surprise hit! It was featured in dozens of tech and design blogs, and briefly climbed the app store rankings. As the app’s popularity grew I continued to iterate and add features including a Percentage key, iPad compatibility, In-App-Purchase themes, widgets, and a scientific keyboard. Apple featured Numerical at various times, and it went on to be downloaded 500k times, and currently has an App Store rating of 4.8/5 stars.

This is the app that launched my freelance app developer career, and the lessons that I learnt about development, iterative design, and marketing have influenced all of my future projects.