I've recently started work with an organisation that is rapidly expanding and is recruiting or growing several development teams (including two web-based products and a data warehouse/BI team). They are basically working to agile methodologies but haven't formalised a standard way of working yet.

Despite the fact that it is early days, I've been surprised by the lack of tools being used to manage the development processes (e.g. no issue tracker, no tool to manage the product backlog etc.)

Although it's not my primary responsibility, I'd like to help them out with some recommendations on the most important tools they should get in place.

What are the 3-5 top priority tools to establish for management of a good development shop? Why are they necessary? How do they improve the software development process, and how do I justify them to my bosses?