Diegos' learnings from building and growing a calculator app

Meet Diego Sebastian.

Diego is from Bogotá, Colombia. He is a graphic designer who worked in the branding industry for about four years before learning and transitioning into coding. This shift opened up new opportunities for him

Diego co-founded two app startups: one of which didn't make it, but the other has been thriving for five years, generating direct client revenue.

He has also been involved in several freelance projects, helping other startups and businesses develop their branding and digital presence.

Currently Diego is very focused on numms - a calculator app with history.

The story told by Diego Sebastian

My background

My background in graphic design has provided me with a different perspective on product design, which has been invaluable in what I create now: Indie apps.

Combining these skills has allowed me to approach app development in a more integral way. On one hand I understand the power that aesthetics has on the audience and on the other, I'm aware that beyond its looks, a product has to be valuable in a usable dimension to be wanted by the users. Aesthetics and function cannot live without each other.

What is numms?

Numms is a calculator app with a persistent history: think of it as a notepad for numbers.

It includes all the common functionalities of a basic calculator, but with the added feature of being able to save your numbers across one or more sheets. You can store your own customized memory values.

The app is fully responsive, adapting its UI whether you're using a tablet, a phone, or even the Stage Manager on an iPad. Additionally, it offers a dark mode for ease of use in low-light environments.

Beyond its core functionalities, numms is designed to enhance productivity by allowing users to keep track of their calculations without losing previous data. This makes it particularly useful for students, some professionals, and the average Joe who frequently needs to perform and revisit calculations.

The beginning

I started building numms in November 2022. It didn't start as a calculator though. Initially, it was an experiment aimed at testing layout changes when resizing the app's window; essentially, an attempt to make a mobile app as responsive as a website.

This whole project began as a technical challenge, exploring how to create consistent interfaces across different devices and screen sizes.

As I dove deeper into the experiment, I realized the potential for developing a practical application that combined this responsive design with useful and specific functionality. Numms evolved from a design/coding experiment into a calculator app.

Launching numms

Numms launched in December 2023 on the App Store, and around March 2024 on Google Play due to new guidelines that restrict immediate app publishing.

The staggered release allowed me to refine the app based on initial user feedback from the App Store launch before making it available to Android users, who have a different perspective on usability.

Since its release, I've continuously worked on updates and improvements, incorporating user suggestions and expanding its features to better meet the needs of the user base.

The growth of numms

It took me about one month to get the first 100 users for numms. Just from “organic” word of mouth. Friends and family recommendations, and reddit posting.

So far (July 2024) numms has achieved 703 installations, maintaining a growth rate of 100 users per month on average. Notably, over 98% of these installations are on Apple devices.

The Android user base is still in the early stages of growth, primarily due to the limited marketing efforts directed towards that platform so far.

The steady growth rate and positive reception on Apple devices indicate a promising potential for similar success on users using Android with the right promotion strategies.

Marketing numms

The main struggle in terms of marketing has been differentiating a calculator app from the multitude of similar apps available.

While many apps offer basic calculator functionalities, numms provides a unique experience with features like persistent history, customizable memory values, and responsive design (all in one app).

I've often heard the advice not to reinvent the wheel, but when you dive into development, you realize there are numerous improvements to be made. Marketing these enhancements effectively has been challenging.

My current focus has been on highlighting these unique features and demonstrating how they enhance productivity and user experience, making numms stand out in a crowded market.

You could say it's bootstrapped in some ways, as I've primarily used organic reddit comments and posts to promote it so far. I've tried to focus on participating in relevant subreddits where users are likely to benefit from numms.

Below a few example of my reddit posts and comments to promote numms.

• https://www.reddit.com/r/SideProject/comments/1868drb/numms_a_responsive_calculator_with_history_for/

• https://www.reddit.com/r/ProductivityApps/comments/1868gc0/numms_a_responsive_calculator_with_history_for/

• https://www.reddit.com/r/ipadapps/comments/1869a1n/numms_a_responsive_calculator_with_history_for/

• https://www.reddit.com/r/ipad/comments/18b0idm/comment/kd1x85h/

• https://www.reddit.com/r/iphone/comments/17a8059/comment/kj7twka/

• https://www.reddit.com/r/VisionPro/comments/19b3tev/comment/kj2bffj/

In addition to reddit, I've also relied on word-of-mouth and feedback from early adopters to help spread the word. This grassroots approach has not only kept costs low but also fostered a engaged and supportive user base who value the app's features.

I'm a firm believer that you shouldn't rely on marketing for initial growth; instead, you should focus on retention and building an excellent product first. This approach, while beneficial in creating a solid foundation, has its drawbacks. Relying solely on organic growth and word-of-mouth ensures a steady and solid user base but can limit the speed at which your product gains traction in a competitive market.

However, I've realized that even with a great product, visibility is crucial. The lack of targeted promotional efforts has slowed down potential growth, especially on platforms like Android.

Moving forward, balancing product development with strategic marketing efforts will be essential to accelerate growth and expand the user base effectively.

In terms of monetization I’m not there yet. I’m planning to offer a freemium model with special functionalities once I reach about 5000 users in order to make some testing on that matter.

If you are interested in testing Diegos upcoming app projects, you may visit lummen.co.

If you want to see his graphic design studio work, you may visit diegosebastian.co.

But - there is more. Diegos has quite a few more projects in the making. You can subscribe to be among the first group of users to test them when they launch:

• alsoalso.co - A project manager

• flaggs.co - A travel companion app

• yournal.co - A daily log app

• frammes.co - A community manager app