Recents

Press (the first from the left button) to open the Recents menu. 

Here you can check calls history. Android users can press 3 dots near the number and get additional information about the full SIP number, the time the call was made, and its duration.

Open

All missed calls you can check by pressing and opening the corresponding tab. 

Open

Deletion mode 

By pressing the first button in the upper right corner , you will open the calls deletion mode.

Open	Icons meaning  - to select some numbers;  - to delete selected entities; - to exit the deletion mode.