Cross-platform messaging utility WhatsApp has disappeared from the Windows Phone Marketplace, as reported by WMPoweruser. We reached out to the developers for comment on this removal, and they replied:

Thanks for the email.

Yes, we are aware. We hope to submit a new version to the Marketplace as soon as possible.

Sorry I don't have more details at this time.

According to WPCentral, the app has been hidden, rather than pulled, and speculates that the app may be returning with a $0.99 price tag. Available for iPhone, Android, BlackBerry, S60, and Windows Phone, WhatsApp has served as a free SMS replacement, recently adding features like group chat and threaded messaging. If the app has simply been hidden, WhatsApp will likely return once its developers sort things out with the Windows Phone Marketplace. Users that have the app already loaded don't need to worry — it will continue to function as usual.