I am not sure whether a feedback on Covidence belongs here, but I will go ahead and share my suggestions on how this tool could be improved.
I have been using Covidence for the screening process of a systematic review and there are a few deficiencies that I encountered along the way:
1. There should be more flexibility within Covidence concerning the allocation of references in the title/abstract and other screening stages across different reviewers. In our title/abstract screening phase it is me screening all references and 2 other reviewers are each screening half of the same references (all references are screened twice independently by different reviewers). The only way that the second screening can be divided up between reviewers is to create two separate projects. It would be nice if one could allocate studies within the same Covidence project to different reviewers.
2. In the different screening phases there should be the opportunity to leave a comment for difficult references, to inform the other reviewers what the difficulty was with classifying certain references. This is particularly important in the stage where references labeled with "Maybe" are being screened again by a third reviewer.
3. There should be the possibility to create customized folders within the project e.g. to keep (for the review) irrelevant but for a different purpose interesting references (for example, to be used in the discussion section).
4. Covidence has difficulties dealing with too many references at a time. Thus, the capacity of the software needs to be increased by a lot.
5. References should be listed on different pages, so that e.g. for every 20 new references one needs to go to the next page. The problem right now is, that Covidence manages to display the first 1000 references (which is a struggle) but after that it's impossible to see any more references. It's important though to see these other references, for example to review ones' own decisions on study eligibility and to maybe change these decisions again.
6. Going along with No. 5, it would be helpful if one had more options to filter references, e.g. by decisions (Maybe, Yes, No) awarded.
7. In the folder "Waiting for other reviewer" one can change ones' own vote another one time, not more. This should be unlimited.
8. There should be an option to include a third or forth screening stage if necessary. So far there are only two screening stages available.