AppExchange application installation best practices

1)  Check edition compatibility

Verify that the app only includes components that are compatible with your Salesforce Edition.

1. Search and open the app listing on the AppExchange.
2. Scroll to the Requirements section of the listing.
3. Under "Salesforce Editions," confirm that your edition is listed.
 

2)  Maximum custom object or custom tab requirements

Since AppExchange apps can include custom objects and custom tabs that will add to your organization's total limit, confirm that the app's new components will not cause you to exceed the maximum limit.

See our Salesforce Developer Limits Quick Reference documentation for more details.

3)  Check external services

If your new app has a reference to an external service, make sure you have access to that service.

Example: For an app that links to Google Maps for Account management, access to Google Maps would be required for the service to work.
 

4)  Test drive

Most apps have "Test Drives" available for use. As a read-only User, you can take a test drive of the desired application before installing to review the core functionality.
 

5)  Install the app in a Developer Edition or sandbox

Before you install an app into your production organization, first install the app into a recently refreshed sandbox to test the application beyond the constraints of a read-only User.

On sandbox organizations, you'll be able to create, edit, and delete records, and see how the app interacts with other customizations you have within your organization.
 

6)  Install the app in your production organization

If you're happy with the functionality of the app after testing, install the app to your production organization!

Note: If you encounter the error "Unable to find User," create a Trailblazer account and try to install the package again. See Sign Up for a Trailblazer Account in Salesforce Help.

See also
Install a Package 
Understanding Packages