The Ledger add-on provides tracking and simple accounting for your inventory. Record increases, decreases, including the cost(s) you assign to the items.
In addition, as of version 1.1.1, the Ledger now has an item performance graph:
This illustration allows you to easily select lines by clicking on the legend above the graph. By default, they are always on, but clicking one will hide it until you click it back on or refresh the page. This graph can be very useful to visualize the stock over time as well as reservations made over time. Reservations are plotted on the grey line and this is the only line that is plotted against the right axis. All other data lines are plotted against the left axis.
A license entitles you to one year of support and updates.
Please note that this plugin requires a properly licensed version of WP Inventory Manager in order to work.