Performing daily independent activities can be a challenge for people with Down's Syndrome (DS). This article investigates how to better support these activities with smart devices based on three cycles of a collaborative participatory action research (PAR) process. The first cycle involved semi-structured interviews ( n = 4 ) with parents and an online survey ( n = 39 ) with people with DS and their parents to explore barriers and opportunities for independent activities. This cycle highlighted that travelling independently was a common challenge among discussed barriers to independent activities for young adults with DS, an issue that smart devices have the potential to overcome. The second cycle involved seven focus group discussions ( n = 20 ) with parents ( n = 13 ) and young adults with DS ( n = 7 ) for gaining deeper insights into barriers to independent travel. We explored key barriers to independent travel and gathered design requirements for smartphone apps to overcome these barriers. In the third cycle, we designed a digital prototype based on participant recommendations and conducted seven focus group meetings ( n = 19 ) with caregivers ( n = 12 ) and individuals with DS ( n = 7 ). This final cycle reviewed the proposed digital prototype and validated the key barriers found in the second cycle. Overall, our studies confirmed that mobile technology can support people with DS in performing daily life activities that increase social inclusion. The studies resulted in identified barriers and requirements along with co-designed solutions for independent travel apps.