This add on is activated on the opal page of universities in Saxony. Its main functionalities are those of allowing bulk upload and download of student submissions. This addresses a long standing problem of opal that lead to the teaching staff spending 20 seconds for uploading and or downloading each student submission for any given assignment. These 20 seconds quickly added up when dealing with classes of 20 or more (which is fairly common). This add on allows to make this process in an automatic and fast manner and, moreover, provides you with statistics regarding the assignment such as average grade, standard deviation, number of students whom have submitted and number of submissions that still need marking. A full description of the add-on as well as its source code can be found in the following link.
