Our productively went through the roof by getting organized and that's basically what those sites are. There are many, wrike iand trello are popular also
I use it to organize employee tasks but I use it for SEO efforts also. I have a board with each url from my site then I add to it exactly my efforts. Like the url, page type, then how many links I've added, the date, anchor text etc. It let's me view it in different ways too so I can tell if I am not giving enough love to certain pages. It's good to be organized and doing it with excel works too but I prefer an organisation app. I have the app on 2 devices and use the site on my computer, they all link together. Helps with scaling up to the next level. They give a free trial and that's what got me sucked in, after that I was hooked, cant go back to not using now.