Is there an app for managing bookmarks?

I have always avoided Safari, it seems OK but for one thing, Bookmark organisation is pathetic, but for once Mozilla have totally screwed up there browser by releasing Firefox Quantum with has made the browser totally useless and very anti Java which for us as a company means that we now have to either use Chrome or Safari, the only problem that I have now is to find a way to organise over 1500 bookmarks in safari.

I have tried just moving them around in the sidebar, but this often fails and is just way too clunky and not exactly user friendly.

Can anyone recommend an app that can manage the bookmarks within Safari?

James