One Small Step: Green Living is a free iPhone app developed by The Neighbourhood Effect Pty Ltd. It aims to help individuals make sustainable changes in their daily lives to combat climate change. The app uses behavioral science to provide step-by-step programs and recommendations for eco-friendly habits.

With One Small Step, users can gain clarity on the environmental impact of their choices and receive a personalized sustainability roadmap. The app also offers programs to switch to sustainable options, such as ethical superannuation funds, and provides guidance on making the switch.

To keep users motivated, One Small Step offers gamified programs and a habit tracking tool. Users can earn rewards for taking climate action and see their impact in real-time. The Teams feature allows users to complete weekly challenges with friends, family, and colleagues to achieve sustainability goals together.

One Small Step believes that individual choices can have a significant impact when people act together. By helping users reduce their carbon footprints, the app aims to contribute to the UN's goal of 2 tonnes of CO2e per person per year by 2050.