Digital Lifestyle Intervention for Lung Cancer Survivors

This study tests a digital lifestyle program designed to help lung cancer survivors stay active, eat well, and manage stress using a smartphone app. The program is tailored to people recovering from lung cancer treatment, with the goal of improving their quality of life and long-term health. **You may be eligible if...** - You are 18 or older - You have been diagnosed with non-small cell lung cancer (NSCLC) - Your life expectancy is at least 6 months - You are currently in rehabilitation, or you finished surgery, chemotherapy, or radiation within the past 24 weeks - You can read and understand German - You have access to a smartphone or tablet **You may NOT be eligible if...** - You have serious mental illness or physical limitations that would prevent participation - You do not have access to a mobile device - You do not understand German Talk to your doctor to see if this trial is right for you.