Is there a third-party app that allows me to restrict users from editing invoices and quotes once they have been created?

Thank you for posting your question in the Community, user94108. I'd be happy to share information about integrating third-party apps with your QuickBooks Online account.

QBO has established partnerships with numerous third-party application developers. This allows you to enhance QBO's capabilities with a wide range of add-on features and services from these integrated apps.

To explore all available app integrations, the easiest way is to access the Apps menu directly within your QuickBooks Online account. Here are the steps to find and evaluate potential app integrations:

1. Go to the Apps menu and proceed to the Find apps tab.
2. Click the drop-down beside Browse category and select a category. This will open the QuickBooks App Center marketplace
3. You can browse or search for specific app categories/features you need
4. Read the app descriptions, reviews, and pricing details
5. Select any apps you want to purchase/install and integrate with QBO.

The Apps menu and integrated App Center provide a centralized way to seamlessly find, evaluate, purchase, and install third-party apps that can be integrated directly with your QBO account.

Allow me to share these additional resources about using third-party apps: 

• Transfer App Ownership Or Disconnect Apps In QuickBooks Online And Accountant
• Disconnect An App In QuickBooks Online And QuickBooks Online Accountant

The articles cover important topics like transferring app ownership if needed, as well as properly disconnecting apps you no longer want to be integrated.

Feel free to continue posting any other questions you have in the Community forum, user94108. The entire QuickBooks Team is here to provide guidance, whether it's getting started with new app integrations or managing your existing connected services down the road.