Your case requires to be investigated by Technical Support, please contact http://parrot.com/hotline . Please share the maximum details available, serial number of the Flower Power, version of the app, version of the firmware, model of smartphone used to monitor your garde, version of the OS installed in the smartphone. Thank you.
....This app used to allow monitoring multiple plants with one device. As of today this is no longer possible. The company wants you to spend to the tune of $50 per device in order to monitor different plants as the app wont allow to program multiple plants to one device..................
The URL in the middle/grey column of the documentation page seems to be invalid (gives a 404 error).
Fortunately the URL in the right/black column (Python code) works (at least as of today 2016-06-03):