Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Instagantt - Instagantt is a powerful and intuitive Gantt chart tool to enable teams to plan, manage and visualize their projects easily. Manage your schedules, tasks, timelines, and workload like a Pro. Try it for free.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
Manifold - Manifold GIS is a combination of mapping, CAD, DBMS and image processing.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.