Inclusion Criteria:  Main diagnosis for the Pulmonary Rehabilitation is an International Classification of Diseases-Code J44.- (Other chronic obstructive pulmonary disease) at all 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifications A-D and stages 1-4. Internet access at home owning a smartphone with the operating system Android or iOS basic computer and internet skills (e. g. using web browser) ability to operate a smartphone (especially to install mobile applications) ability to read, write and comprehend as well as communicate electronically  Exclusion Criteria:  severe concomitant disease, which will affect the ability to be physically active more than COPD for example, cancer or severe cardiac, neurological, orthopaedic or metabolic comorbidities) cognitive impairment that hampers study implementation Lack of ability to speak German