Citation Management: A solid citation management software is key for any systematic review. I would not do a SR without one. When you are dealing with possibly thousands of studies, you need a way to manage all of them.
Abstract Tracker: My world was rocked once I was introduced to abstract trackers for SRs. Once you have gathered all of your studies in your citation management software, you can export them directly into an abstract tracker software. This software will automatically track which studies each one of your team members includes, excludes, etc. many of them will even track your PRISMA flowchart for publication. If you do not use an abstract tracker, you will be manually tracking everything using Excel spreadsheets and a lot of time.
"Review Manager (RevMan) is the software used for preparing and maintaining Cochrane Reviews. You can use RevMan for protocols and full reviews. It is most useful when you have formulated the question for the review, and allows you to prepare the text, build the tables showing the characteristics of studies and the comparisons in the review, and add study data. It can perform meta-analyses and present the results graphically."