SmartCrawl is a free plugin from wpmudev and you can also buy the Pro plugin as so you will need a subscription to download and install the plugin. They have a lot of plugins that we use for most of our clients so I would advise looking into them if you haven’t yet.
I have been using the wpmudev Plugins a lot since I started on wordpress which do the works as any other premium plugin would, but this plugin has not only won my heart but it works as I wanted it to , although I am using the free version but it has performed much better than any other plugin on net.
Some features I liked best :