Viber was pretty popular here (Spain) before WhatsApp supported voice calling. People used them side by side, Viber for voice, WhatsApp for text. Now WhatsApp dominates everything, with Telegram coming in a very distant second. Telegram seems popular for groups because I believe it doesn't show everyone your phone number. A lot of Teachers seem to setup Telegram groups for their students so their student's don't see their phone number.
That's very true and such a nice feature! I think the one time I ever used Telegram was to send my girlfriend a multi gigabyte video file, so she could forward it into her student's Telegram group from her phone.
