As guy who had over 3 years work in quite many start-up companies. I understand that management tools is a very important thing that managers should take time to think about it, and answer all questions as “What management tools we should use?, how to assign tasks? how to track tasks?, how to review tasks? and how to manage workflow? … etc …”. Because, It is easy to know that if your company size is 2-6 employee, it seems that without management tools and workflow, you are still able to operate company only with email, Skype or face-to-face. However, if you had a plan to grow up your business, you should think about management tools and workflow that will be help you operate your company efficiently.
The below is my suggestion that I have ever used in my works
Perfect email solution for small, medium business. Actually, if you have ever used Gmail, you will realize that no other one is better. Additional, Gmail supports company domain (e.g: [email protected]). And used Gmail, you will be used the other wonderful products of Google as Google Driver, Google Calender. Fortunately, you do not have to pay too much for business. Google Price is so suitable.
Actually, It seems impossible to fully replace Microsoft Office by other one. Google Driver contains in its inside biggest concepts is cloud-computing and social network. It is so easy for you to sharing or many people who locate anywhere to compose a document at the same time together. Better that you thought, Google Driver is making communication faster, the world is being flatter and warmer. Google Driver supports you free 1.5 Gigabyte capacity. If you need more, you should pay money. No worries, Google price is very reasonable.
Booking room, meeting, conference have never easier. You just need to choose time, address, description, add people, and click to create your calendar. Google will be notify the participant via email and SMS immediately to confirm the attendant. And they are reminded when it is due. Google Calendar is 100% free.
Asana, Jira or Trello
If you need a system that you could create a task, assign to members and track when it is done. Then Jira or Asana can help you. Asana is younger than JIRA. So you will feel comfortable the user experiences of Asana. However, JIRA support many APIs that you can use to integrate to many other systems.
Slack, Hipchat & Skype
Chatting help you can contact other person instantly. Skype is good choice. But a software company should use Hipchat that is easy to integrate with other system like Jira, Git.
GitLab, Github (github.com) or Bitbucket (bitbucket.org)
If your company works in software industry. Then source version control is very important thing. You can use SVN, but my suggestion is GIT. Github and Bitbucket work basing on GIT with web interface. Those make you feel easy when working with branch, commit, tags, fork, code review.