First things first, let's set up a collection called "Scores" to keep track of user scores. You'll need these properties:

• User: This is a relationship property that links to the Users collection.
• Score: A numeric property to store the actual score value.

Make sure your Users collection has at least these fields:

• Name: A text property for the user's name.
• Total Score: A numeric property to store the user's cumulative score (this one's optional, but handy if you want to keep a running total).

Next, create a new screen for score submission. Add a Form component that will:

• Use the "Scores" collection.
• Include fields for user selection and score input.
• Link the user to the score using a dropdown menu that references the Users collection.

Now, add a new screen named "Leaderboard" where you'll display the leaderboard.

Add a "List" component to show items from either the "Users" collection with aggregated scores or directly from the "Scores" collection:

• Set the list to sort by score in descending order so the highest scores show up at the top.

Customize the List cells to show the necessary info:

• User's name.
• Score (if you're using the "Scores" collection) or the total score (if you're aggregating in the Users collection).

If you need to, add filters to the list to show scores based on specific criteria, like:

• Date range.
• User categories.

Add navigation links so users can easily access the leaderboard from other parts of the app. This could be a button or a navigation bar item.

Finally, test the whole flow:

• Submit scores via the form.
• Check if they show up correctly on the leaderboard.
• Make sure the sorting and filtering work as expected.