Inclusion Criteria:  Patients eligible for inclusion in this study have to fulfill all of the following criteria:  Written informed consent is obtained before any assessment is performed. Males and females age 16+ years. Genetically confirmed FSHD. Symptomatic as demonstrated by Lamperti score >0. Fully functioning Android-based smartphone with Android version 5.0 or higher. Able to comply with the study procedures, prohibitions and restrictions (drug use) as specified in the protocol.  Controls inclusion criteria  Controls eligible for inclusion in this study have to fulfill all of the following criteria:  Written informed consent is obtained before any assessment is performed. Males and females age 16+ years. Unrelated subjects without FSHD. Fully functioning Android-based smartphone with Android version 5.0 or higher. Able to comply with the study procedures, prohibitions and restrictions (drug use) as specified in the protocol.  Exclusion Criteria:  Patients fulfilling any of the following criteria are not eligible for inclusion in this study:  Current or previously diagnosed illness or any clinical condition that, in the opinion of the investigator, might confound the results of the study. Positive urine β-human chorionic gonadotropin (β-hCG) pregnancy test at Screening in women of childbearing potential. Wearing a pacemaker or other internal medical device (e.g. Vagus nerve stimulation (VNS), Deep Brain Stimulation (DBS)). Current enrollment in an interventional study.  Controls fulfilling any of the following criteria are not eligible for inclusion in this study:  Current or previously diagnosed illness or any clinical condition that, in the opinion of the investigator, might confound the results of the study. Positive urine β-human chorionic gonadotropin (β-hCG) pregnancy test at Screening in women of childbearing potential. Wearing a pacemaker or other internal medical device (e.g. Vagus nerve stimulation (VNS), Deep Brain Stimulation (DBS)). Current enrollment in an interventional study.