Stacks - Task manager!

Wrike's end-to-end solution takes your projects from initial request to tracking work progress and reporting results. With Wrike, you'll be able to create and delegate tasks, track deadlines, visualize your plans on the Gantt chart, and share reports. If needed, you can use advanced features like Custom Workflows, advanced security, restricted data access and more. Wrike is a powerful yet user-friendly solution that helps you achieve your project goals.

Todoist is a task manager thats useful, fast and easy to use.

Taiga is a full featured project management platform for startups and agile developers & designers who want a simple, beautiful tool that makes work truly enjoyable.

Asana is a web and mobile collaborative work management app that goes beyond typical collaboration software by enabling teams to track everything they're working on. With tasks, projects, conversations, and dashboards, Asana lets your team know who's doing what by when to help you get results. Use Asana for team communication, setting meeting agendas, running brainstorms, sharing files, or creating shared calendars--anything you can think of. You can also add partner integrations to customize Asana for your team with functionality like Gantt charts, time-tracking, and Google calendar sync. Asana is available on web, iOS, and Android and is free for teams of up to 15 people. »

Workflowy lets you organise your brain into easily manageable lists. It also works as a single-pane outliner with inline notes. It offers one-click hoisting (zooming into branches). The online version syncs with mobile apps.

Trusted by 11,000+ businesses, JIRA is the leading bug tracking, issue tracking and project management tool. JIRA combines issue tracking, agile project management, customisable workflow, and a pluggable integration framework to increase the velocity of your software development team.

Wekan, formerly LibreBoard, is an open-source and collaborative Trello -like kanban board application.

Take your tasks anywhere with this feature-packed application.

Wrike's end-to-end solution takes your projects from initial request to tracking work progress and reporting results. With Wrike, you'll be able to create and delegate tasks, track deadlines, visualize your plans on the Gantt chart, and share reports. If needed, you can use advanced features like Custom Workflows, advanced security, restricted data access and more. Wrike is a powerful yet user-friendly solution that helps you achieve your project goals.

Kanboard is a simple visual task board software.

Take quick notes on Post-It(r) like sticky notes on Windows desktop, stick those notes to websites, documents & folders. Set reminder alarm to each sticky note. To avoid desktop clutter, you can organize those sticky notes inside folders. Send sticky notes to another computer over local network (LAN) or Internet, Sync sticky notes between computers using the Notezilla.Net cloud service, access your sticky notes on any smart-device such as iOS(iPhone/iPad), Android, Windows Phone, Blackberry etc. »

Basecamp is a web-based project collaboration tool that allows groups of people to share files, meet deadlines, assign tasks, and centralize feedback.