In addition to being one of the most widely-used messaging apps around, WhatsApp gets another thing really right that its competitors often drop the ball with — supporting old versions of the operating systems it's available on.
On June 13, 2018, WhatsApp revealed that it'll continue to support Android 2.3.7 and older versions of Gingerbread until February 1, 2020. Seeing as how the first version of Gingerbread was announced in 2010, that means WhatsApp will officially support that iteration of Android for ten years.
That sort of commitment is seldom seen with most major applications, so we need to tip our hats to WhatsApp's promise here.
Even though the company doesn't have much to gain from this sort of support as just 0.3% of active Android phones were running a form of Gingerbread as of the June 2018 Android Distribution Numbers, WhatsApp is doing so anyway.
As for our iPhone friends, WhatsApp will also continue to work on iOS 7 through that same date.