Hi Beto,
Usually, using a Client ID for web applications should work in hybrid mobile apps. However, there is a better solution which I will explain below.
The scenario you would like to accomplish could be achieved in a mobile app using the Google + plugin for Cordova. The plugin is available in this
repository. Download the archive as a ZIP file from GitHub and follow the instructions from this
documentation article about how to install it in your AppBuilder project.
Using this plugin would add the same native SDKs that are used in native applications and provide similar user experience to your audience.
Using the authentication workflow in mobile apps as used in web sites may be a reason for the vendor stores to reject your app.
Let me know if this helps.
Regards,
Anton Dobrev
Telerik