WhatsApp, the cross platform instant messaging app for smartphones, announced on its blog Friday that it would stop supporting a few operating systems (OS) by the end of the year.

The company said it will stop support for BlackBerry, including BlackBerry 10, Nokia S40, Nokia Symbian S60, Windows Phone 7.1, Android 2.1 and Android 2.2.

"While these mobile devices have been an important part of our story, they don't offer the kind of capabilities we need to expand our app's features in the future," the post said.

"This was a tough decision for us to make, but the right one in order to give people better ways to keep in touch with friends, family, and loved ones using WhatsApp. If you use one of these affected mobile devices, we recommend upgrading to a newer Android, iPhone, or Windows Phone before the end of 2016 to continue using WhatsApp," the post added. 

The company, which was bought by Facebook in 2014 for $19 billion, said the world has changed largely from the time the company started seven years ago.

"When we started WhatsApp in 2009, people's use of mobile devices looked very different from today. The Apple App Store was only a few months old. About 70 percent of smartphones sold at the time had operating systems offered by BlackBerry and Nokia. Mobile operating systems offered by Google, Apple and Microsoft — which account for 99.5 percent of sales today — were on less than 25 percent of mobile devices sold at the time."

WhatsApp in early February said in a blog post that it had crossed the one billion user mark.