Trello, monday.com, Redmine, Airtable, Workflowy, CherryTree, NocoDB, Dynalist, TiddlyWiki, Dendron, AFFiNE, Ardoq, Cryptee, Pure Writer, Tixio, DayViewer, Docstell, Sticktail, Baselance, Reactivepad, Papyrs, Socialtext are some alternatives to Doit.io.