ClusSync app

[Gremlin]

One presumes that OneDrive is a Microsoft provided/backed/owned service. Therefore they would have a "legitimate" interest in preventing "unknown" apps from accessing the OneDrive system (authenticated user or not). I can quite understand that an app provider may balk at submitting their work to Microsoft and I presume that Microsoft may charge for the privilege.
I do not use Cloudsync or OneDrive (Intrinsically I just don't trust them either) but for those that do, just brushing it off seems a bit lax. If you provide an app that interfaces with some other app - and you claim it does - then you have to do whatever is required to make it work. If that process is too onerous, as it may well be over time, then stop claiming it works. (Or if you broke it, fix it,)

[TMroy]

For most cloud service providers, to enable cloud access and data synchronization, we first need to register a developer ID for the application, obtain access permissions, and agree to comply with their policies. However, this does not mean that the completed application requires verification from the service provider, nor are they responsible for the quality of the application. In short, TerraMaster is responsible for the software quality.