WhatsApp to end support for Nokia, BlackBerry systems

'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.'

Popular instant messaging service, WhatsApp, has announced that it will be ending support to particular devices by end of 2016.
According to a press release issued on February 26, the service just turned seven years old and is putting an even greater emphasis on security features and more ways to stay in touch with the people that you care about.  
Considering how people's use of mobile devices has changed since their launch in 2009, WhatsApp has decided to end support for WhatsApp Messenger running on Nokia and BlackBerry operating systems:

'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.
As we look ahead to our next seven years, we want to focus our efforts on the mobile platforms the vast majority of people use. So, by the end of 2016, we will be ending support for WhatsApp Messenger on the following mobile platforms:
BlackBerry, including BlackBerry 10 Nokia S40 Nokia Symbian S60 Android 2.1 and Android 2.2 Windows Phone 7.1 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.
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.'