Dutch architectural firm?Waterstudio?has engineered flood-resistant City Apps, which use available space on water to convert slum dwellings into useful structures. These waterborne structures built from standard sea-freight containers with solar panels on the roof and floating foundations of recycled plastic bottles are suitable for installing and upgrading sanitation, electricity, water filtration, medical clinics, community kitchens, workshops, classrooms, housing and communication. They can quickly add essential services to adapt to cities? changing needs and can be moved easily to where they are needed most.