Sicher

I love the Sicher functionalities and have no complains about the software as such. But from a message system you have to rely on the fact that your messages are being sent. When you send a message often you can see on the indicator that the message is not transferred. When you close and open Sicher it most of the time functions again. But sometimes the indicator shows that the message is sent (it shows a 'ticked' sign) but the other party doesn't receive it.
This makes the software pretty useless, especially when you are not really chatting real time and you don't know if someone has sent you a message yes or no.