FastFit — Intermittent Fasting Tracker

İzni Burak Demirtaş
4 min readMar 28, 2024

Hi everyone 👋,

You can also read this article on my blog.

In line with my 2024 goals, I wrote that I want to develop my own products/applications and share my processes within the framework of the #buildinpublic concept. As the first output of these goals, I would like to tell you about FastFit — Intermittent Fasting Tracker application.

FastFit — Intermittent Fasting Tracker Application

First of all, let me give brief information about the application: We can say that it is a useful application where you can apply intermittent fasting plans in a simple and easy way, you can access information about it, in addition to these; it has extra features such as daily water drinking, weight and body measurements tracking. As someone who has made intermittent fasting a lifestyle since April last year and experienced it, making an app to help with this was one of the first ideas that came to my mind and I rolled up my sleeves.


First of all, I started with competitor analysis. Examining similar applications gave me very good ideas in terms of both design and functionality. Using platforms such as Notion, Miro, etc., I created some documents with the information I obtained from these platforms. I tried to think about which features the application would include. My priority was definitely not to drown the application with non-functional features, not to make a dense application; to create a product that is as simple, fluid and suitable for the main purpose as possible.

Along with competitor analysis, I also worked on keywords. I used tools such as MobileAction and AppTweak and received support. Thanks to these tools, I analyzed the app stores (App Store, Play Store) of the countries that are my main focus.


After completing the necessary preparations and analysis, I started the project quickly. Since I am developing a mobile application, I first identified the technologies I will use in this field. Then I tried to identify other technologies and packages that may be required for the application I will make.

I can list some of the technologies and tools I used as follows:
React Native, Expo, Redux, Firebase (Firestore, Remote Config, Analytics, Functions), RevenueCat (+ Paywalls), OpenAI (ChatGPT), Golang, NodeJS, Figma

The most difficult part of developing the application was the design. Because I did not have a clear source on design. I tried to come up with a design myself with the inferences I made from competitor analysis, and while doing this, I tried to create a product that was as simple and useful as possible. I don’t know how much I was able to achieve this, because as you know, I’m not designer. So I might have spent a little too much time on this. Of course, I am planning to get professional support for UI/UX in the coming months (if I can find a suitable designer friend).

I gave priority to the Apple platform and focused on the iOS side in order to make a fast development and to take full advantage of the advantages and audience of the platform. Although it is very fast to output to both iOS and Android since I use React Native, I never focused on the Android side during development and did not want to waste much time.

I thought about concepts such as chart packages to visualize data in the application, local notifications to provide information to users, multi language to appeal to more audiences and tried to prepare a suitable infrastructure. After the use cases, user flows and general purposes of the application were completed, I focused on the App Store side and focused on ASO work and the creation of application information for the Store (screenshots, title, description, keywords). Since I thought of America as the main market, I worked on language support in German, French, Portuguese and of course Turkish, especially in English and Spanish. While preparing these, I made great use of tools such as ChatGPT, DeepL.


I published the app on the App Store as of March 22, 2024. In less than a week, there were about 250 downloads, 5 subscriptions, 2 purchases for ad removal. It earned about $10 via Admob, but the ads were very few and limited. In the first month of launching the app, I wanted not to show too many ads and not to bore users too much in order not to have a bad effect. In the coming weeks, I can analyze the data and make updates on this issue.

Download FastFit from the App Store

For the Android side, everything seems to be ready now, but I haven’t released it yet. If nothing goes wrong, I want to release the app on the Play Store in the first week of April at the latest. I will also follow the process there.

These are the updates I can share for now. I will try to share and inform you as developments occur over time. I hope it will be a good process.

If you have such projects, ideas and product development curiosity, if you want to get ideas and talk about the topics you are curious about, you can contact me using the communication channels. I would be happy to meet, talk and exchange ideas :)

If you want contact to me, you can check my X profile or my personal page.

Thanks for reading and have a nice coding!
İzni Burak.



İzni Burak Demirtaş

nam-ı diğer Buki. 👨🏻‍💻 Sr. Software Engineer @Jotform — #php #golang #javascript #reactnative — Co-Founder at HaberSistemim & MemleketApp