Let me introduce the tools we use to manage projects, enhance client communication and track time task by task.

Track project progression : Trello (Web, Windows, MacOs)

First, let speak about tools to replace our paper todolists, todo.txt, todo.xlsx, outlook reminders etc... Kanban method is not only trendy but also a great way of tracking project progress even for clients that are not used to the agile methodology. In this area, Trello is still the best : Free for small projects, fairly easy to configure and to understand. One pitfall however : the user management is not clear and you need some practice to be sure that your customers can access and modify the board without problems.

Is there an API ? : Yes (RestFul and easy to implement)

Some alternatives solutions ?

• If you can't use online tools, for example when working for a private company that doesn't allow that, Todolist from AbstractSpoon is a wayyyy better choice than just a todolist in Excel or notepad. Moreover, it can run as portable for using it from an USB key for example.

• GitHub projects (and issues management) also do the job pretty well but needs a github account for each user who want to access it. Not user friendly for clients.
  Is there an API ? Yes, and libraries ready to use with .NET and other languages.

• Remember the milk : As the name suggest, this tool is oriented more like a todolist. You can organize tasks by tags and list. The approach is different from the other tools : it groups your tasks in an “inbox” which is feeded every day with the tasks to achieve in this day. The bonus point with this solution is that you can connect it with Siri and so speak with your phone : “Siri, remind me to bla bla bla” and get the task automatically synced with all of your devices. You can also make lists of lists of lists for better organization, something that is not possible in Trello nor Github Project.
  Is there an API ? Yes, Restful and Easy to implement

Chat and audio communication : Slack (Web, Windows, MacOs)

Everything that allow to avoid email chaining is a good choice. Slack is a good candidate for this task. It allow you to communicate with your customers and other teams members as a simple chat, of course, but the real added value in slack is apps integrations that allow connection with trello, github and other services... This allow customers to be notified of code changes, tasks attribution etc... and makes your work more transparent and so, gives customers more trust in it.

Data backup is ensured for a sufficient amount of time and you can search in the chats and uploaded data fairly easily.
Is there an API ? : Yes RestFul, OAUTH2, relatively easy to implement.
Origin : US

Valuable alternatives :

• Whatsapp private groups
  Origin : US (property of Facebook)
  Is there an API ? No and it won’t have it in a near future. Facebook stated that it’s not in the philosophy of the service of having an API to allow connection with external services.

• Telegram private groups (widely used in the
  cryptocurrency world)
  Origin : Russia
  They claim that privacy is one of their priority but, IMHO, it should be verified to ensure.
  Is there an API ? Yes but very hard to implement. However, there is a nice and easy implementation in Python.

• Skype conversation rooms.
  Origin : US (Property of Microsoft)
  The fact that Skype is already used by a lot of people could justify Skype as a nice option. However :

  • The UI changes on a regular basis and without prior notice.
  • NO BACKUP OF CONVERSATIONS which, from my point of view is really a bad point. I get screwed by this multiple times.
  • Searching in uploaded files or chats content is not optimal. I also get screwed by this multiple times.
    Is there an API ? There is but it seems really complicated to use.

• Discord (also widely used in the cryptocurrency world but was initially made as an alternative to TeamSpeak, a gaming oriented chat app).
  Origin : US probably
  Is there an API ? Well, I don’t think so.

Time tracking : Toggl (Web, Windows, MacOs, Android, IOS)

Toggl is a simple timer with some nice features like :

• Automatic reminder every X minutes if the timer is off that you should track your time
• Ability to organize times tracked in project, and project organized by clients
• Free detailed reporting that can send directly to your clients to justify time spent on each project
  API ? Yes, restful but never used

Screen sharing : join.me (Web, Windows, MacOs, IOS)

join.me is a tool made by the LogMeIn team. The free version allow you to screen share to max 3 persons with the free version and up to 50 with the pro version. Also can be viewed from a tablet if you need to show something to... you know... people in vacation ;).
API ? Yes, RestFul but never used

Valuable alternatives :
appear.in : limited to 30 minutes but allow multiuser screen sharing