PowerPoint add-in PPT Productivity lets you specify a horizontal gap or space between objects in PowerPoint, for perfect spacing.

Quickly specify the horizontal gap between one or more selected shapes or objects on your PowerPoint slide. For example set the horizontal gap between selected shapes to be 10pts or 4pts (you can enter whatever number you prefer). Perfect for making PowerPoint shape spacing exact and consistent.

The Set Horizontal Gaps feature is in the Gaps group on the Format Toolbar.