All they'd need to do is publish an open API. Then people could control the device through, for example, Home Assistant. Some of the Andersens are OCCP compatible which should mean that they can be controlled by an OCCP compatible application.I think the only way that would happen if the developers of the app helped out and gave us some inside knowledge of any safe mode or way to connect to the charger, in reality most people only used it for setting Octopus Go charging times.
Its a standard problem with IOT devices- if they are dependent on a remote server then they are bricked if the manufacturer takes the server offline. Open APIs or something like Home Assistant integrations are the future.