Fluidic games blur the line between gameplay and game design, providing playful, non-technical, easy-to-use tools for users to design their own games. We introduce Wevva, our first fluidic game for iOS, which allows users to design and share their own games based on novel mechanics, entirely on a mobile device, with no need for programming skills. The development of such software is a significant challenge in user interface design, requiring a new design approach compared to the design of more traditional creative tools, and with much scope for mixed-initiative co-creation and other assistive AI technologies. Our aim with fluidic games is to democratise game design, allowing anyone and everyone to express themselves through the artform of digital games.