This is one of two Akeeba extensions I install on every site. There are many combinations and levels of security you can implement with Admin Tools. It is a fairly user friendly extension, but I do recommend reading the documentation to get the most out of it. If you don't know what you are doing, you can lock yourself out of the site. Not a fault of the extension, but of proceeding without reading. Thank you for all the hard work, Akeeba!