Most of you all must be getting paid to say these things, I however am not.
Nevertheless, you're missing out if you haven't tried TickTick, it's on every platform (Not just web apps only, although theirs resembles Asana), but their mobile apps are the best. Think Things3 meets Todoist or Microsoft Todo/Wunderlist.
Another Omnifocus contender (and way more affordable) is 2Do. Mac and iOS only I believe, but it's packed to the gills for your GTD.
For project mgmt. All apps are going to be slaughtered by ClickUp. Just telling you the truth from the year 2030. ;)