@jeroens - Not with Tempy. Tempy devices will direct their information to the Tempy.io website (where you will sign up for an account and start to view incoming data from your devices). You won't be able to modify the device programming or direct the information to any other services with the specific Tempy devices.
That said, you will be able to purchase the unaltered devices that we are using for Tempy yourself and then can program them and direct the information to any service that accepts webhooks (HTTPS). We are also going to be building an MQTT integration into the new mcCloud service.
Hope that helps!