Want a video tutorial on the Interactive Legend? Click below:
The Interactive Legend 
(also called the Filter Legend) is the window that appears at the right of the app when launched. A great deal of information can be determined about the data in your app by referring to this tool.
Use the Layer dropdown to specify which layer is displayed currently on the map. Use the Display By dropdown to change the field within the selected inventory that is shown.
You can see how many features are currently displayed on the map right below the Quick Filter dropdown. Note that this count is a count of all geometries in the inventory, not just living trees. Consequently, the counts in the Stats tool versus the count found in the Filter Legend may vary slightly.
By clicking on the check boxes next to each item in the legend, you can hide or show any collection of points. Toggle between a pie and bar chart by clicking on the tabs that say Pie and Bar. Finally, under Options, you can hide or show data labeled as “Not Specified”.