Just reporting the installation guideline below is not working (at least for me) Is there something I'm missing?, I'd appreciate any clue.
M-x customize-variables RET org-modules and then ticking the "drill" check box. (well I also tried with another pckge (
org-learn.el) which installation is (also, I'd say) not (properly) documented. The output I got is:
Problems while trying to load feature `org-drill' Problems while trying to load feature `org-learn'