Hi balance4you9995wf3dl, welcome to Thunkable! 
Be sure to check out How to ask Great Questions v2.0, the Community Guidelines, and our Getting Started Guide to make the best of your Thunkable Community experience!
For individual apps, the limit is 50mb, regardless of the plan selected. The 1gb is for total account storage. The project storage remains at 50mb per project to ensure that apps will get approved for publishing in either the App Store or Google Play Store.
More information in our docs: Assets | Thunkable Docs
To reduce the project size we recommend that you either compress the files or use a third-party video hosting service like Cloudinary. It is very simple to integrate their hosted files with Thunkable.