From Shopify Wiki

Do's

Test Your App

1. Your application must work. If you need/want beta testers, request an invite for our testing google group with a short introduction to your app (so that we know it's not spam): https://groups.google.com/forum/#!forum/shopify-app-beta-testers

Smooth Installation & Onboarding

1. Make the installation as seamless as possible.

2. Information like shop name, email and an address can be easily retrieved by making a request to the shop. A user should not have to enter this information in.

3. Pre-populate data your application requires prior to the user using your application. They gave you access when they installed your application and need no confirmation afterward. It is much easier to determine what an application does if there is data rather than a blank canvas.

4. Ensure that if your application integrates with other software that the user understands what he or she must do to get your application running.

5. If there are any special instructions the user must follow make these instructions stand out.

6. If your application only retrieves data after the date of your application's install ensure that your application receives new data from the shop.

Submitting Your App For Review

1. Submit screenshots of your application as it helps us review your application and will ultimately help users figure out if your application will help them.

2. Make sure your application can be tested by Shopify. We cannot test what we cannot access.

3. Any third party accounts should be setup for us or tell us how to set them up ourselves.

4. Ensure that your application description accurately describes what the program does.

5. If your application has no interface like that of a fulfillment service then you will be required to modify information in a test shop to test the functionality of your application.

6. Make sure you provide accurate contact information so we may contact you to get this process started.

Don'ts

Submission

1. Don't submit an application for review that is for testing. It will be deleted. If you want to test the install process for your app, follow the instructions on the authentication page in the docs. Specifically you need to generate a url that looks like this:

http://<shop url>/admin/api/auth?api_key=<API key>

2. Don't submit an application for review that you have not tested. We would like to get your app approved and on the app store as soon as possible! To do this we need to test your application and any bugs we might find will delay that.