To install the PRO Key you just go on Google PlayStore and buy it. Reboot your device after installation. Please do not remove free version of the application.

calcoli_elettrici_prokey Electrical Calculations Pro Key
Icona Calcoli Illuminotecnici Pro Key Lighting Calculations Pro Key
Icona Spesa Elettrica Pro Key Electrical Cost Pro Key
Icona RaspController Pro Key RaspController Pro Key

To purchase the PRO Key you must associate a credit card or a prepaid card to your Google PlayStore account. In some countries you can also pay with phone credit and PayPal. It isn’t accept other payment methods.


Yes, you just login to Google PlayStore with the same account that you used to purchase app and it will possible reinstall the applications that were previously purchased.
No, has not an expiration. It will be use for ever.
Updates existing languages or make a new translation for Android or iOS: download translation file, translate it and send it.

Calcoli elettrici Translate Electrical Calculations
Icona Calcoli Illuminotecnici Translate Lighting Calculations
Icona App Spesa Elettrica Translate Eletrical Cost
Icona App RaspController Translate RaspController

If your country isn’t into list Paid app availability, you can purchase the app on Amazon. In this case you need to install the Amazon App Store and the you can buy the PRO Key.

calcoli_elettrici_prokey Electrical Calculations Pro Key on Amazon
Icona Calcoli Illuminotecnici Pro Key Lighting Calculations Pro Key on Amazon
Icona Spesa Elettrica Pro Key Electrical Cost Pro Key on Amazon
Icona RaspController Pro Key RaspController Pro Key on Amazon

If your ProKey is invalid, please uninstall the free application and the ProKey. Reboot your device. Now go to PlayStore (with the same account used for purchase) and reinstall first the free application and then the ProKey purchased.
Permission is required to validate the serial number. You can find more information in the ‘Privacy Policy
No, you can’t transfer the license.
The app is distributed by two different Stores: PlayStore for Android and iTunes for iOS.