kmail
full featured graphical email client
KMail supports multiple accounts, mail filtering and email encryption.
The program let you configure your workflow and it has good integration into
KDE (Plasma Desktop) but is also useable with other Desktop Environments.
digikam
digital photo management application for KDE
Digital photo management program designed to import, organize, enhance, search
and export your digital images to and from your computer.
amule
client for the eD2k and Kad networks, like eMule
aMule is a peer-to-peer file sharing application, designed to connect
to the eDonkey and Kad networks. It has a wide range of features,
including many of the original eMule client, like: