We knew it was coming, but Telegram is finally making voice calls available to its millions of users around the world.

The mobile messaging company revealed way back in 2015 that it had developed encrypted voice-calling technology some time ago, but it just wasn’t a priority in terms of rolling it out. And in January this year, CEO Pavel Durov reaffirmed that it would add calls at some point. From today, Telegram users in Western Europe will be able to access voice calls on Android and iOS, with the rest of the world getting them “very soon,” according to a blog post.

Founded in 2013 by Durov, who also helped set up Russian social network VK, and his brother Nikolai, Telegram has emerged as a notable player in the competitive chat app space. This, in part, has been due to the company’s focus on encryption and privacy. Last year, the company announced it had passed 100 million monthly users.

With audio calls, Telegram is once again touting its encryption, similar to the technology that powers its secret chat feature that lets users delete messages or schedule them to self-destruct. But for calls, it has developed a new key-exchange feature that enables the caller and receiver to compare four emoji over the phone — if they’re the same, the call’s safe.

Telegram voice calls have one particularly interesting feature — users can control who can and can’t call them through Telegram. For example, if you have a mixture of friends, family, and business acquaintances who use Telegram, you can stipulate that “Anybody,” “Nobody,” or “My Contacts” are able to call.

But feeding into that, you can add or remove specific users to your permissions list — this means you can permit everybody to call you with the exception of one or more people (e.g. that annoying auntie). Or you can stipulate that nobody can call you — with the exception of individuals you specifically name-check.

Telegram has been slow to offer audio calls, with the likes of WhatsApp offering such a feature for two years already. That Telegram has finally added audio calls feeds into the broader convergence trend from across the mobile messaging realm. Indeed, WhatsApp finally added video calls to the mix a few months back, similar to other apps already out there, and we can perhaps expect Telegram to do the same in the future.