The badge on the iPlum app shows the unread messages and voicemails. Separate badges on Message, Recents and Voicemail inside the app show the corresponding unread count.
How to increase or decrease iPlum voicemail storage?
How do I set up my voicemail?
How to create custom or professional voicemail greetings for iPlum?
I am not seeing my voicemails in the app?