Closing your web browser or logging out will not stop your running virtual devices.
Make sure to stop your devices manually.
If a virtual device is started from the web interface and it is not in use, it will keep running until time out (default is 30 minutes).
To avoid unwanted charges or consuming your free 60 minutes trial, make sure to stop your device as soon as they are unused. To do so, please refer to Stopping a virtual device
Virtual device timeout can be set from the Administration panel, in the Settings section. See Administration settings
If a virtual device is started with gmsaas, time out will not apply. The device must be stopped with gmsaas as well.
See gmsaas user guide.