Backlinks shows you the number of links pointing to any URL, for free. From total link count, to .edu and .gov links to even the exact number of unique referring domains, dive into your competitors' backlinks, fine tune the results and export to CSV.
Site Audit by Ahrefs is a cloud-based crawler that will scan your entire website (no matter how large it is) and report everything that is wrong with it from an SEO perspective. User-friendly UI and a variety of visual reports will help you make sense of the data and present it to your clients.
Ubersuggest is a keyword suggestion tool that now support domain level metrics.