No. 38 · 26 Jan 2026 · 6 min
CHLNG: 1x1 friendly sport challenges.
From idea to product in 6 weeks.

Hey,
I hope you’re all doing very well. 🙂
I hope you all had a great time with your friends and family, and had a great break to focus on things that really matter to you. In the last weeks, I noticed that more and more people started subscribing to Sportflow (which is weird to me, because it was more active in the last months and growth stopped altogether 🙂), but I want to share a bit of what’s going on and what’s next.
This episode presented by:
Superapp - Build iOS apps with AI. Your technical co-founder for iOS
The current status 🔥
Sportflow was a very big part of my journey so far. It’s a resource that helped me grow in the industry, enter areas I never thought I could, and work with my confidence and fears. For me, the only goal was to share interesting products, a new vision, and talk to the people. I would appreciate everyone who subscribed and stayed with Sportflow.
In the last few months, I had some changes in direction, and didn’t have too much time to update you with interesting products, case studies, etc. I made a deep dive into the AI and vibe-coding, made some test projects, and started CHLNG.
Something that I started as a side project quickly became a serious thing, where I currently spend my whole free time moving it forward. Shortly, Sportflow stays as it is, and I will continue to share my observations about the industry and products, but I also want to share the story behind the founder experience and how it goes by the end.
I personally think that this kind of content will be very useful for those who are building, or just dreaming to build a product. I literally have zero experience, and that’s why it’s even more exciting and interesting for me. I am always starting with a question: how far away can I go?
What is CHLNG? ⚔️
The idea of the product itself came from my personal experience. As far as I remember, in my childhood, we had different internal competitions with my friends all the time. From bench presses to pull-ups. It was never something special, but day-to-day activities to have some fun. The most interesting part of this is that I’m continuing to do this even now. We are still having a competition in 100 m swimming time by time with my friends who are living in Lithuania, discussing how it goes. At some point, with the help of AI, I understood that I wanted to wrap everything in one working prototype or product.
CHLNG is an ultimate app for 1x1-friendly rivalries and gamified fitness.

How was it built? 💻
Today, we’re entering the era where product people can prototype, build, release, and create their own products. You can debate, refuse it, but if you find the right use case for AI, it turns into a superpower for you and your company or product. My personal case was that:
I had an idea
I wanted to build an app specifically for iOS as a prototype
I found a Superapp (AI-vibe-coding tool that builds and focuses exactly on swift development)
I started prompting
I noticed it’s really doing what I need (in terms of visuals/functionality)
I continued to develop an app
When we talked about tech-stack, it’s always up to you what you’ll choose. In my case, I know that I want to build first in the Apple ecosystem as it gives me more opportunities. That’s why I found Superapp by coincidence, and it became a tool for me, which started to move things forward. I think that I was able to release the first beta for TestFlight in 4 or 5 weeks. For a person who never developed a product by himself, I think it was a really good progress, taking into consideration that it includes some logic and special mechanics in the concept.
As I mentioned before, it’s so important to understand your use case and why you’re actually using this or that tool in your workflow. My answer was clear. I tried another vibe-coding tool, but Superapp gave me exactly what I needed at that point. If I see a great product, I will promote it. If you have an idea and want to build your first native app on iOS, Superapp is a good way to start.
By the way, I already had an online workshop on how to build your first app with Superapp, and you can read about it here: read it
I’m going to do the next one, and if you’re interested, drop me a message on LinkedIn.
User research 🧠
Since my first idea and prototyping, every single day, I see more and more interest in the product. Before I even started, it was one of the first times when I decided to validate the idea.
I used several methods to validate the idea and to understand the real need.
Another case, where I used AI for Synthetic data and user interviews. For me, it was a very interesting part, as I understood that I need to interview people to get a proper understanding of the user needs, but I also wanted to use AI tools to speed things up a bit. I split my work into 2 parts.
I’ve used synthetic interview data from 3 different sources for 15 people. In total, I had 45 interviews + started real interviews to validate and compare with real data.
Results and scoring are shown below.

The main reason why I did it was that I wanted to check how close the real score is to syntethic one. As you can see, after the 10 interviews, we can see that number aren’t different that much. Based on my scoring system, the product goes into the "Promising” category what is a very good sign.
Where is CHLNG right now? ⚔️
Currently, I have a fully-working prototype for the first beta users. I have people who are using the app, giving me feedback, and I can iterate, fix bugs, improve robustness, and add some new features. I can say it’s hard. Currently, it feels that you’re working as a developer, and you don’t have enough time to work on other important things.
Something that started as a side-project with a goal to improve AI skills turned out to be a product that is aiming to completely change the approach and behavior in amateur sport. I want to bring joy back to amateur sport. No pressure, but social connection, accountability, fun, gamification, and trust.

As I’m currently located in Germany, Bremen, I had an opportunity to present a product at the Startup Pitch Night, and I didn’t expect this kind of interest in the product. Just today, I got another message to join Beta (as one woman wasn’t at the event, but heard about the product). I’ve received another email with the request for an Android app and further ideas.
Only this one event brought a lot of new interesting connections, insights, and even a clearer sign that I’m going in the right direction.

In the upcoming month, I have already planned at least 1 event (or even 2) and another meeting for potential collaboration and growth. We haven’t yet released to the App Store, as I’m too demanding of the visuals, mechanics, and the rest.
Having a working website, a fully working MVP, market research, user research, and an absolutely clear vision for the product, something that I can’t imagine even 3 months ago. All of this happens because AI is already shifting the industry.
You might ask, ok, another tracking fitness app. No, it’s not another tracking app. We’re focusing on social connections with the people you actually know. We turn your workouts into a fun and joyful playground. Anytime. Anywhere.
What’s next? 👇
I think I can talk about this for long hours, but another confidence that I got was that 2 people already reached out to me and want to join as Angel Investors. That’s something I didn’t expect at all, but it gives me just a clear signal that it’s definitely more than 1 person believes in this idea. I didn’t even ask about the amount of money. It doesn’t matter at this point at all; it just shows something completely different.
All the best.
Cheers,
Taras