Sibo/Psion Series 3a
These GUIs don’t have this feature.
EPOC R5/Psion Revo
Phone dialer in EPOC R5/Psion Revo with thanks to Daniel Beardsmore
This application is usually used not for dialing, but for synchronizing contacts between a phone and the contact database in the OS.
EPOC R5/Psion Series 7
This GUI doesn’t have this feature.