About Fieldio

How did Fieldio come about? It's easiest to explain if I introduce myself first. For several years now I've been a football coach in amateur youth football. Something that landed on my plate unexpectedly when the previous coach of my son's team stepped down. I grew along with the team from U8 up to U11 for the 2026-2027 season. Coaching the squad is something I do with a lot of joy and passion. As an amateur youth football coach, every Saturday (match day) brings the same hectic challenge: putting the team together and building the rotation plan. And on top of that, making sure everyone gets equal playing time. That's turned out to be a tricky bit of maths every single match — especially when you don't have an assistant on the touchline to help you out.

For amateur football coaches there are plenty of apps that help you build training drills or keep an overview of your matches, but none that help with the line-up and rotation plan. Coming from a product and marketing background, I started using AI to make life easier for myself. First with ChatGPT, constantly calculating fair playing time and keeping the running totals. But it was hard to do that on-site and adjust last minute when players arrived late or dropped out that morning. It also became one giant chat with no overview. So I started building something with Google AI Studio, a free AI tool that lets you create websites and apps. It's a bit more technical, but with my product and marketing background I got a long way and at some point I had my own app on my phone that I was using for my own team. I showed it to other coaches and they were really positive — they recognised exactly the same scenarios and challenges.

To make it easier for them too, I wanted to expand the app and make it more professional. Until then it was purely set up for my son's team. During the off-season I started properly extending the app, with the goal that both clubs and individual coaches could use it on their own. The first thing I did was write out the full logic of fair opportunities and fair playing time, so the AI could work it into the line-up and rotation plan. In youth football this is an important rule at various federations such as the KNVB. I looked at which other data points matter, so the AI assistant has enough information to build a solid rotation plan for every match. And it worked. The AI assistant now generates the line-up and rotation plan with a single tap. As a coach you can of course still adjust it — keeping that control and freedom was really important to me. The AI truly acts like an assistant. Once the match has started, it also reminds you of substitutions and the agreed-upon minutes. That was one of the real-life scenarios: forgetting to keep track of time.

Another important factor was that I wanted the app to be accessible to every football coach. Using AI intelligence in the app does come with costs — costs that grow with the number of users. That's why there's a free version where you can do everything manually, and a paid version that covers the cost of the AI assistant. The paid version is free to try for 30 days, because it genuinely saves you a lot of time and hassle as a coach, and that's well worth the small monthly price. Afterwards you can always look back at how playing time was distributed — so if there's ever a discussion from parents, the app gives you the data to end it.

During the season, parents were often on the sideline, but so were grandparents and other family members or friends. Those who couldn't make it wanted to be kept up to date on the match through a quick message. So I built a live widget into the app with a unique URL for each team. As a youth coach you can share that live widget with parents, and they in turn can pass it on to anyone at home who wants to follow the match. This feature is completely free and works more as a nice extra. In youth football, scores and results aren't recorded by the KNVB up to U11, but players and parents clearly enjoy them and always ask about them. So I started tracking everything — which is exactly what this app and live widget do.

Every match is archived. As a youth football coach you can therefore use this app to look back at the results of every match you've played. All you have to do is start the match in the app each time.

The goal I have with this coaching app is to make match day easier for coaches in amateur football. No more stress from last-minute changes or forgotten substitutions. Just enjoy the match and the joy of the players — which is exactly what match day should be about.

So give it a try for free! And if you have ideas, or something unexpectedly doesn't work as expected, the app has a built-in feedback feature. That way you help make it even better for every youth coach out there.

Have fun,
Martijn
Youth football coach
AS'80 Team U11