Slack is great tool to chat with your team. The daily work in a team is, however, more than pure communication, and that's where Slack is reaching its limits. As you're looking for an alternative for Slack, you probably already know that.
Stackfield provides exactly what you need every day: A clear group chat, an extensive task management with various display options (kanban or list style), an easy to understand file management and a functional calendar. All these features are combined in Stackfield and our end-to-end encryption ensures that all relevant data are secured. In addition, all data is solely stored on servers in Germany.
Another advantage of Stackfield compared to Slack is that an installation on your own servers is possible, while there's no Slack self hosted version (also called "on premise") available. This means that with that version all data is processed on your own systems and not passed to other parties. With the on premise version of Stackfield, it's also possible to connect it to a Active Directory or to customize it.