The devices are battery powered (topped up by the solar panel) and you configure them through the app via your smartphone.
The device probably uses a Bonjour or WiFi Direct system that the app on your phone then uses, through your phone wifi, to give you the ability to configure the remote device to connect to a router (I.e. from WiFi Direct (ad hoc) to infrastructure mode so it can then connect to the Internet and communicate with the cloud service the company offers.