@enniom Hello!
If I understand correctly, you would like to offer a free app for your users, which can be downloaded from Google Play Store? Possibly with different name and logo? The app would only allow pre-defined GUI (e.g., reading from an initialization file that is part of the application itself), standard GUI-O functionalities for creating widgets would be unavailable.
Although this is technically possible, it requires a lot of resources (manpower) to maintain this kind of service. I can look into this a bit further, but I believe it is currently impossible to offer this service.
Best regards,
kl3m3n