Pro Precedents / Pro Dependents. When used, a box pops up that lets you clearly/quickly see all the all the cells (and their values) used in the calculation of the cell being audited. Makes reviewing your own model that much faster, and it's even more valuable when auditing someone else's model. There's also a significant amount of customizable shortcuts that really save time when it comes to formatting, colour coding, etc.

Most useful features to me are the excel shortcuts. Love the ability to customize the formatting shortcuts and the productivity shortcuts do save quite a lot of time.

Excel productivity tools PowerPoint slide management