Our work / WCWijzer for MDL Fonds
8,000 toilets on the map — and #1 in Navigation on iOS.
WCWijzer tells you where the nearest suitable toilet is, in seconds. Built for MDL Fonds, the Dutch digestive-health foundation, it maps more than 8,000 verified toilets across every Dutch municipality and puts them one tap away on iOS and Android.
For MDL Fonds the need was both a mission and a business one: turn a well-evidenced public-health problem into a product people would adopt, reach a national audience fast, and maintain the data afterwards without a standing engineering bill. The app had to launch on a fixed date — World Toilet Day — and earn its place on people’s home screens.
The Netherlands is a toilet desert — one public toilet for every 12,500 people, against Germany’s one per 4,762. MDL Fonds’ own research found that one in five Dutch people avoid activities for fear of not finding a toilet in time, and nearly one in four sometimes stay home. For the 1.1 million people living with a chronic digestive condition such as Crohn’s or colitis, the result is isolation, anxiety and shame — a daily limit on where they can go. MDL Fonds wanted to remove it.
One public toilet per 12,500 people in the Netherlands, against one per 4,762 in Germany.
One in five Dutch people avoid activities for fear of not finding a toilet in time.
Live with a chronic digestive condition that makes reliable toilet access essential.
Launching on World Toilet Day gave the release a news hook. WCWijzer reached #1 in Navigation and #2 free app overall on iOS, with downloads up 400% to more than 48,500.
A Payload CMS lets a small team manage 8,000+ listings, verify new locations and grow the map without a developer in the loop — keeping running costs low and data in-house.
Expo gives one codebase across iOS and Android, Supabase delivers fast location search, and Vercel keeps hosting reliable — fast where it matters for users, cheap to run for a lean team.
The product was shaped in a co-creation workshop before a line of code — why a six-month build hit both its date and its market, and why the roadmap kept delivering after launch.
We started with co-creation rather than a brief. Over a two-day definition workshop, the Lab Digital and MDL Fonds teams shaped the strategy, design direction, feature scope and technical architecture together. Exercises like a “worst app ever” session and concept walkthroughs kept the focus on what someone in urgent need requires.
From there we designed for one job above all — finding the nearest suitable toilet in seconds — and built and launched native apps for iOS and Android, grounded in input from the patient panel, volunteers and MDL Fonds staff.
Co-creation workshop — a two-day definition workshop shaping strategy, design direction, feature scope and technical architecture together.
Design and build — design grounded in the patient panel and volunteers, focused on one job, then native iOS and Android apps on Expo with a Payload CMS the client runs itself.
Launch — released on World Toilet Day, 19 November 2025; #1 in Navigation and #2 free app overall on the iOS App Store at launch.
Community-led iteration — user-suggested locations and reviews added on demand, plus the WC Pas feature on Nationale Poepdag to unlock extra locations with a code.
One codebase, native iOS and Android apps.
MDL Fonds manages the toilet data itself, without developer help.
Fast location-based search over verified geo data.
Reliable, low-maintenance hosting.
Built directly by Lab Digital with MDL Fonds — no third-party delivery partner.
MDL Fonds brought the lived experience of its community through a patient panel and volunteers; Lab Digital brought product, design and engineering. We made decisions together from the first workshop — the app was built by people who need it.
The community kept shaping it after launch too: when users asked to add their own locations and see reviews, we built it, and we added the WC Pas feature on Nationale Poepdag so patients, donors and organisations can unlock extra locations with a code.
WCWijzer launched on World Toilet Day, 19 November 2025, and reached #1 in Navigation and #2 free app overall on the iOS App Store. Downloads grew from roughly 12,000 at launch to more than 48,500 across iOS and Android — 400% growth — and it now maps over 8,000 verified toilets across every Dutch municipality. Within six months, 10 municipalities had asked MDL Fonds for advice on their toilet policy, unprompted.
WCWijzer went on to win gold (charity/non-profit and government/public sector) and silver (digital for good) at the Dutch Interactive Awards 2026. Each download stands for someone who can leave home with a little less worry.
common questions
Lab Digital defined, designed, and built WCWijzer, the MDL Fonds app that helps people find a nearby accessible toilet, for both iOS and Android.
One in five Dutch people avoid activities for fear of not finding a toilet in time, and 1.1 million live with a chronic digestive condition, yet no trusted nationwide map of accessible toilets existed. WCWijzer is MDL Fonds’ answer.
WCWijzer is a native iOS and Android app built with Expo, with a Payload CMS backend, location data in Supabase, and hosting on Vercel.
WCWijzer reached #1 in Navigation and #2 free app overall on iOS at launch, grew to more than 48,500 downloads across iOS and Android (400% growth), and maps 8,000+ verified toilets across the Netherlands.
About six months, from a two-day definition workshop in 2025 to launch on World Toilet Day, 19 November 2025.
WCWijzer was delivered directly by Lab Digital with MDL Fonds, without a third-party delivery partner.
Yes. WCWijzer won gold (charity or not-for-profit and government or public sector) and silver (digital for good) at the Dutch Interactive Awards 2026.
We help organisations turn a user need into a product that launches on time and gets adopted — from a co-creation workshop through to the app store, on a stack you can run yourself. Let’s talk.