Tile+Brush
When using the Unity Tilemap Editor (UTE) you can use the Tile+Brush instead of the default GridBrush.
The Tile+Brush is installed by default when you install the TilePlus package. The User Guide explains how to revert that if you want to.
Brushes have Brush and Selection inspectors. The Brush inspector is what's shown in the bottom portion of the UTE window. The Selection inspector replaces the normal Unity inspector when you select a tile with the UTE.
The Tile+Brush has replacment Brush and Selection inspectors that can display fields and properties from TilePlus tile instances. Tile+Painter uses the Brush's Selection inspector and a modified version of the Brush inspector when it displays tile information.
For more detailed information, see the User Guide and this.