Telegram Messenger is the blockbuster app of the moment as backlash against the Facebook-WhatsApp merger gathers steam. Anti-WhatsApp sentiment has helped the obscure Russian app to become a top 5 iPhone download in 64 countries as WhatsApp slips. In the classic messaging app bellwether market of Spain, WhatsApp has dropped to No. 20 on the iPhone download chart as Telegram has soared to No. 1. Russian entrepreneur Pavel Durov financed a new messaging app that launched in September 2013. This was widely regarded as a weirdly quixotic move — who needs a new messaging app in the world where titans like WhatsApp and WeChat already have hundreds of millions of active users? As it turns out, Telegram added nearly 5