I'll call you on WhatsApp.
'WhatsApp' is said exactly as in English. 'Ti chiamo' = tee-KIA-mo.
Use this when you want to make a free internet call via WhatsApp rather than a regular phone call. In Italy, WhatsApp is the dominant communication platform.
'Ti chiamo su WhatsApp' = I'll call you on WhatsApp. 'Ti chiamo' = I'll call you (informal 'ti'). This is now one of the most common Italian phrases for arranging a call. Alternatives: 'ti mando un vocale' (I'll send you a voice message), 'ti scrivo su WhatsApp' (I'll message you on WhatsApp).
Mandami un messaggio su WhatsApp.
Send me a message on WhatsApp.
Requesting a text message.
Ho visto il tuo vocale.
I heard your voice message.
'Vocale' = voice message (WhatsApp audio).
Ti mando un vocale così ti spiego.
I'll send you a voice message to explain.
Using voice message to explain something.
WhatsApp has an estimated 43 million Italian users out of a population of 60 million — making Italy one of the highest per-capita WhatsApp markets in the world. 'Mandami un WhatsApp' has become a verb-like expression in Italian ('mandare un WhatsApp' = to message someone on WhatsApp). The 'gruppo WhatsApp di famiglia' (family WhatsApp group) is a cornerstone of Italian family life.