Energy conservation in daily life is an important way to address climate change. This study is set to investigate how effectively a self-developed quiz app teaches sustainable energy use to young people. The app focuses on energy topics, including energy conservation and everyday applications. The effectiveness of the app was compared to a traditional learning method, specifically text-based learning. Seventh and eighth graders either used the app for 45 min or studied a text covering the same content. A third group received no prior instruction. One week later, all three groups took a knowledge test. Results showed that both learning groups outperformed the control group, with the text group slightly ahead of the app group. The study suggests that quiz apps have potential for increasing motivation, but further research is needed to optimize their effectiveness, to catch up with text-based learning or even reach better results.