I need to add checkbox with the days of the week as in this image:
The problem is that I can not find how to do it, I have tried with the library iCheckbox but it is not available.
EDITED
The response of Error404 is fine but I would need the label to be above checkbox not to the right
You can take a look at the DLRadioButton library where, as the documentation indicates, you can create the checkboxes directly from the builder interface. What it really does is create the appearance of a button as if it were a checkbox.
It is not exactly a tick what appears in the checkbox but it can be helpful. These are the examples that they put on the Github page:
