My current app idea is a checklist that the user will use a switch to mark if the task has been done. What would be the best way to determine how many switches are set to ‘true’? I would like to inform the user that 7 out 10 tasks have been completed for example.
Thank you in advance
I would use a list, add an item to a list if the task is complete and compare it to a list that expands everytime a new task is created. In this way you can also set a larger record of completed tasks among weeks or months. Let me know if you need an example 
You are correctly recommended to use the list. Only this should be a list of objects, each of which has the properties you need, such as the task name, the task completion status (and possibly the date when the task was created and completed).
Issues are displayed in the list. If the task is completed, it is selected from the list and then the “completed” status is set. Which control should I select to set the status value? You can use Button, Switch, Button in Data List Viewer, etc.
To check the status of task completion, you will need to create a loop for all records and check the value of their “status” property
Thank you for your reply, I shall look into that 
Thank you Ironchorch_Yo for your reply, I shall look into that