WCWijzer for MDL Fonds

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.

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.

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.