Google warns me about Insync because 1) it has full access to my Google Drive and 2) the developer’s information hasn’t been verified by Google.
Could you please get verified by Google as a developer?
Here’s Google’s warning from the screenshot as text so that this post can be found better:
Remove risky access to your data
This app or service has extensive access to your personal information and its developer’s information hasn’t been verified by Google. You should remove its access unless you’re sure you trust it.