A patent-pending feature of Photosmith, Smart Groups allows you to intelligently group together photos based on capture date and time. This can greatly improve the efficiency by which you can select groups of similar photos when adding or editing metadata in bulk.
The Smart Group slider allows you to have granular control over the quantity of photos per group. To effectively disable Smart Groups, drag the slider all the way to the right.
Smart Groups slider positions are remembered on a per-collection basis.
To select all photos within a Smart Group, tap on a Smart Group header checkbox in Grid View.