The bioisostere replacement tool, FieldStere is a fast and powerful software tool that uses innovative field-point technology, together with a database of molecular fragments, to help guide drug discovery projects and generate new intellectual property. This version includes updates to the science and user interface. It enables researchers using fragment based drug discovery protocols to grow initial leads computationally, giving significant boosts to productivity and diversity. The software works both on projects operating with protein crystallography support and on those without these resources, an area currently under supplied with computational techniques. Unlike traditional pharmacophore approaches, it uses molecular interaction with proteins as a core descriptor rather than 2D structure, enabling diverse active molecules to be described as similar. The software is available as a desktop application or command line interface on Linux, Windows and now also on Mac machines.