Parkinson's disease (PD) is a neurological disorder with complicated and disabling motor and non-motor symptoms. The complexity of PD pathology is amplified further due to its dependency on patient diaries and the neurologist's subjective assessment of clinical scales. This challenge can be addressed by the advances in mobile technology, which can enable objective, accurate, and continuous patient monitoring. Indeed, a significant amount of recent work explores new cost-effective and subjective assessment methods of PD symptoms. For example, smart technologies, such as wearable sensors, have been used to analyze a PD patients' symptoms to assess their disease progression and even to detect signs in their nascent stage for early diagnosis of PD. This review focuses on the use of modern wearable and mobile equipment for PD applications in the last decade. Four significant fields of research were identified: Assistance to Diagnosis, Prognosis or Monitoring of Symptoms and their Severity, Predicting Response to Treatment, and Assistance to Therapy or Rehabilitation. This study starts with 31,940 articles published between January 2008 and December 2019 in the following four databases: Pubmed Central, Science Direct, IEEE Xplore and MDPI. A total of 976 papers are manually investigated and included in this review after removing unrelated articles, duplicate entries, publications in languages other than English, and other articles that did not fulfill the selection criteria. Our analysis shows that the numbers of published papers every year has increased at a constant rate from 2008 to 2015, while the rate of increase has significantly grown from 2016 to 2019. Majority of the papers (62%) were published in the last four years, and 21% papers in just 2019. In terms of the symptoms, gait and tremor are two major ones that researchers have focused on. The trend shows the growing interest in assessing Parkinson's Disease with wearable devices in the last decade, particularly in the last 4 years. Our automated script makes the review easily reproducible for publications published in the future.