Non-expensive methods for measuring heart rate and oxygen saturation are of great importance in the scope of the COVID-19 outbreak to follow up on the symptoms and help to control the disease.Smartphones are widely available and their cameras can be used to acquire relevant physiological data, such as Photo-plethysmography (PPG) signals. Covering a light source and the camera sensor with a finger, it is possible to acquire the camera-based photoplethysmography (cbPPG) signal. Two methods were analyzed in this work, namely using the rear smartphone camera and the flash LED, and using the front camera and device display as a light source. The latter presents more advantages overall - in particular, greater control over the emitted light and finger detection - and better results were found when compared to a reference device.Clinical relevance- This technology allows the pervasive monitoring of the PPG signal using a standard smartphone, providing a tool to evaluate the subject's heart rate and its variability, respiration, blood oxygenation, etc.