Trello, Workflowy, ClickUp, Dynalist, Taskade, Org mode, Zenkit, Tkoutline, Foldout, MyLifeOrganized, Orgzly, TreeLine, LifeTopix, MyInfo, QOwnNotes, Widget-Board, Writing Outliner, CarbonFin Outliner, Natara Bonsai, buzz.opml, Cloud Outliner, Outspline, Cloud Outliner Pro, PopDo, The Outliner of Giants, Vimflowy, Fargo, Deep Notes, Little Outliner, Hiveminder, GoalStream, YouTasks, TodoToday, Happierco are some alternatives to Checkvist.