Siemens
One "Home Connect" cloud account, every connected appliance underneath it - the same shared platform BSH uses for Siemens, Bosch, Neff, and Gaggenau appliances alike.
Connecting
Register a free application at the Home Connect Developer Portal, then paste its Client ID and Client Secret into Athena and sign in with your own Home Connect account - a real OAuth2 login, not a password stored in Athena itself.
What you get
Entities and commands are fully dynamic, built from whatever each appliance type's own API currently reports - so a washer, an oven, and a dishwasher each show exactly the fields and actions that make sense for that appliance, with no fixed per-type list to keep up to date by hand. Updates live over a WebSocket, the same as Miele, including changes made from a physical control on the appliance itself.