First things first, let's add a new collection to your Adalo app. This is where all the ratings data will live.

• Head over to the Adalo database by clicking on the database icon in the left-hand menu.
• Hit the "Add Collection" button.
• Name this new collection "Ratings".
• Add these properties to the "Ratings" collection:
• User (relationship property linking to Users)
• Item (relationship property linking to the item or entity being rated)
• Rating (number property to store the rating value)

Now, let's design the interface where users will submit their ratings.

• Drag and drop a list component (like a Simple List) to show items that can be rated.
• Inside the list, add a button or icon that users will click to rate an item.
• Make sure the list is connected to the collection you want to be rated (like "Products" or "Services").

Next, let's add the components that will let users submit their ratings.

• Add a form screen that will serve as the rating input screen.
• In the form screen, add a drop-down or star rating component based on the rating system you want.
• Connect the rating component to the Rating property in the "Ratings" collection.
• Include two more input fields in the form:
• One field for the logged-in User (Current User property).
• One field for the Item being rated (Current Item property).

Let's make sure users' actions are correctly recorded in the database.

• Set the button or icon added in Step 2 to navigate to the rating form screen when clicked.
• Configure the form submit action to create a new entry in the "Ratings" collection with the input data.

Time to show the average rating next to each item.

• Add a text or rating display field inside the item list created in Step 2.
• Configure the text or rating display to calculate the average rating for each item.
• Use a formula to calculate the average: sum(Rating)/count(Rating) for the selected Item from the "Ratings" collection.

Finally, let's publish the app and test the rating system.

• Click on the "Share" button in the top right corner to publish the app.
• Use different user accounts to submit ratings and verify that the average ratings are calculated and displayed correctly.