The courses on Eliademy are "crowd-sourced", meaning that they can be created by anyone who wishes to do so. This means that the quality can be variable. Some of the courses offer certificates of completion. However, these are not verified nor accredited and are down to the discretion of the course creator. I would suggest that you use the courses for personal interest/gain, rather than for career or academic advancement.
For more information, see MoocLab's review here: Eliademy