PSPKVM is a homebrew application that allows the Vita to run Java MIDlets—essentially, old Java apps that were popular on phones in the mid-2000s.
: The PlayStation Store on Vita does not list WhatsApp or similar modern messaging clients. Furthermore, the Vita’s built-in web browser uses outdated security protocols that prevent it from loading modern web-based services like WhatsApp Web. The Community Perspective
Let’s get the bad news out of the way immediately: