Hello,

Startup screen takes significant time but it seems that all of my applications (for example dropbox) launched at startup are executed AFTER startup screen. So my question is: Why? Why these applications are not launched at time of startup screen and why KDE is NOT prepared for immediate use after this screen?
And second question is: Is there any way how to add some custom applications to startup screen?

Thanks for your hints.

The startup screen covers only the startup of KDE itself only, and does not cover any applications.
It includes the setup of your workspace and session - starting KWin, Plasma Desktop and KRunner for instance.

As far as I am aware, it is not possible to alter the startup procedure at this time.

Esp. regarding droppbox: assume one of your applications blocks for a network connection and times out ~60secs - waiting for random session restore is not necessarily a good idea.
Also you should be able to use your desktop - even iff some other application takes considerable resources starting up (but you could still check your mails while digikam checks the database or whatever)

If you want to startup dropbox
a) automatically
b) during the startup phase
that is possible by hinting it in the desktop file:

--- snip "~/.kde/share/autostart/dropbox.desktop" ----------------
[Desktop Entry]
Exec=dropbox-client # or whatever is the command
Hidden=false # set true to prevent startup
X-DBUS-StartupType=wait
Name=DropBox
Name[x-test]=xxDropBoxxx
Type=Service
X-KDE-StartupNotify=false
OnlyShowIn=KDE; # yesno - whatever you think
# and EITHER of
X-KDE-autostart-phase=0
# OR (XOR!)
X-KDE-autostart-phase=BaseDesktop
-------- /snip -----------------

I can not say that I would encourage to do so, or in this particular case i'd actually DISCOURAGE to do this.
You have been warned, don't cry if you run into trouble.