BVSTools recently released GreenTools for G Suite (G4G) v12.00 which includes the ability for you to create your own applications that use Google APIs for use within your G Suite environment.
As you've seen, Google has been tightening down on their API use which in turn has affected the usability of our G4G Suite of products.
We've also been asked if we offer a basic G4G software package that allows the end users to create their own programs utilizing the OAuth 2.0 functionality of G4G such as token creation and refreshing.
With the latest version of G4G you can do just that. We have also put together a large piece of documentation that leads you through the step of creating your own applications within your G Suite environment (note, this is NOT for use with gmail.com accounts, only accounts set up in G Suite for your own domain). There is also a sample application included with in the documentation.
When creating applications within your own G Suite enviroment and setting them up as local, you will not be tied to the very strict regulations put in place for application creators who create public applications, especially with the GMail APIs (and I'm sure Drive and others will follow).
This setup does NOT require the use of a callback website. If you wish to set something up with a web interface that does use web callbacks, we also have something like that available if you wish as well.
Feel free to contact us with any questions, and thank you for all your continued support and ideas.