Click the 'Schedule' tab (1) in the top right hand menu bar. Select a meal on a specific day (2).
This will reveal the search bar (3). Search for a recipe.
Select the recipe you want to schedule, and click the 'Schedule' button (4).
Check the days on which you want to schedule any leftovers of this recipe (5), and click the 'Done' button (6).
You can drag and drop recipes within the plan (7). To delete a recipe, click and drag it toward the bottom of the screen where a garbage can will appear (8).