Users are asked to share their location with Tinder so the app can recommend people within a certain distance. To make that feature work, Tinder has to record the last known location of each user.
Serotonin is known to be the most responsible in terms of neurotransmitters and depression. Serotonin is responsible for an array of functions most importantly being the mood and perception of a person.
Serotonin is a neurotransmitter that plays an important role in the regulation of mood, sleep, pain, appetite, and other behaviors. The excess release of serotonin by MDMA likely causes the mood elevating effects experienced by MDMA users.