Most design principles travel well between different kinds of digital products. The ones that don't tend to become obvious quickly when you start working on something built for children.
Digital Marmalade has designed and built digital products for young people across several different contexts. Ollee is a digital companion for 8-11 year olds, funded by BBC Children in Need and created by Parent Zone, that helps children explore their feelings about school, family, friends and the world around them. MyJourne is a Medical Research Council-funded tool that looks at how the mental health of secondary school students can be monitored. The MAC app, built for King's College London, supports 15-18 year olds through mindfulness-based therapy. Each one required a different approach to the kind of brief we'd handle for an adult audience — and the differences go well beyond making the fonts bigger.
Safeguarding changes the design from the ground up
When you're building something for adults, a lot of the responsibility for how they use it sits with them. With children, that shifts. Safeguarding considerations touch almost every decision — how data is collected and stored, what the product asks for, how it talks to young users, what happens if a child shares something that raises a concern. These aren't things you can layer on at the end. They shape the architecture from the start.
For Ollee, the content design had to be warm and open enough to encourage honest expression, while being carefully bounded so the tool couldn't be used in ways that might harm a vulnerable child. Every piece of content was reviewed against that tension.
Age range matters more than it seems
It's tempting to treat "children" as one audience. In practice, the gap between an 8 year old and a 15 year old is huge — in reading level, emotional development, digital confidence and the topics that are appropriate to address. MyJourne could handle more complexity than Ollee. The MAC app, aimed at teenagers in therapy, required a different register again — closer in some ways to an adult mental health tool, but with the added weight of being used by young people in a clinical setting.
Getting this right means thinking about the assumptions built into every design choice — whether a gesture is intuitive to this age group, whether a metaphor lands, whether the tone of a notification is right for a twelve year old on a school morning. A reading-age filter on the content helps, but it's only part of it.
Designing for two users at once
Children's digital products often have two users in practice: the child the product is built for, and the adult who gave permission for them to use it. Designing for both — without the parent or carer layer making the child-facing experience feel supervised or clinical — is a real balancing act. The MAC app has a carer component alongside the young person's own view. Both need to work well on their own terms, without either undermining the other.
Standard accessibility thinking applies here too, but with an extra dimension. A digital product for children has to work for young people across a range of reading abilities, developmental stages and levels of experience with technology. Assuming a level of digital confidence that not every child has is one of the more common mistakes in this space, and it rarely shows up in testing unless you're testing with real children rather than adults guessing how children might behave.
What this means for a brief
If you're building something aimed at children or young people, raising the safeguarding, content design and age-appropriateness questions early makes them much cheaper to answer properly. These aren't constraints that sit alongside the brief — for this kind of product, they largely are the brief.
If you're working on something in this space, get in touch and we can talk through what's involved from the outset.