Got everything working in my app now - thanks to your help. One question: what exactly do my customers need to do to use one of the offered cloud services? Apart from registering for the appropriate service on their PC that is.
If your app provides a valid client ID and secret, a customer should be able to authenticate and retrieve a valid access token by using the login credentials associated with account for the service. There is nothing else the customer needs to do.
Ok, thanks Bart.