The application appears only on their website, the one you have mentioned above. The only way to obtain additional details on how to acquire it is through direct contact with them or with their representatives (brances). To find the correct branch representative, access the link posted below then click your area which where you live and the contact details will be shown on the left side of the screen. Use those details to contact the developers to ask for Plantvisor.
Branches page: http://www.carel.com/branches