Instance Slider lets you add new instances and define the interpolation values (setting your own weight and width values) using sliders and a live preview.
Insert Instances helps you to create a quick way a X number of instances and select the type of distribution and formula you want to use: Pablo Impallari, Lucas de Groot or a Lineal formula.
Show Interpolations calcules all active instances and draws them behind your paths using a transparent lavender color. It also allows you to align these instances to a selected node.