What softwares/tools do you use most at work that make your life easier?

I have to work with complex projects that contain many resources from personnel to various materials and equipment. Therefore, I need a powerful asset management tool that will help to allocate resources and implement required resource allocation methods. For example, to implement the famous critical path methods, I need a robust critical path solution that will offer different visualization features, including a Gantt diagram. That is why I choose GanttPRO - a smart PM tool with great functionality for resource management. It makes my professional life easier.

Asana + Slack!

Its gotta be gmail/slack/twitter. What about for you?