Urban Trees & Urban Druids are two twin mobile apps designed for the Serious Games and Virtual Reality MSc of the Glasgow School of Art in the context of my dissertation research.The research investigates gamification strategies for environmental data sensing citizen science projects, which are linked to climate change and environmental monitoring research.Both apps are tailored after the phenology project "Natures Calendar" by Woodland Trust, which was used as a case study. Each app follows a different game design approach.Urban Trees is a gamified app offering a single player experience with points, badges, levels and a leaderboard as game elements.