This means that you can copy and redistribute the material in any medium or format. You are also free to transform and build upon the material.
However, when doing so, you must give appropriate credit to the authors, and indicate if any changes were made to the original material. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
Moreover, these tools are developed and proposed here free of charge which means that you may not use the materials for commercial purposes.