Sorting is enabled in Task list, Categories and Completed tasks
To sort a list by any property you have to click on the icon next to the property name.
In the Task list you have the options to sort by: Task name(alphabetically),Priority(Tasks with priority on top), Categories(alphabetically), and Deadline
In Category list you have the option to sort by Category name(alphabetically)
In the Completed tasks list you have the options to sort by: Task name(alphabetically),Priority(Tasks with priority on top), and Categories(alphabetically)
The first time a sorting icon is clicked it sorts tasks and categories by the properties described above.
The second time it reverses the sorting