For the 6.1.1 I am also working with a 6.1.1 GTK client. It has some more functionalities than the web client and it works a littlebit more convenient. Especially because I can open documents without downloading them and pollute my download directory with them. And when a function in the webclient doesn't work or doesn't work as expected I have a workaround with this GTK client.
So I wonder if a GTK client 7.0 is available or planned.