Fart and Facebook apps are missing from the Apple Watch's library, and there is a clear reason one of the two is unavailable.

Facebook has acknowledged the absence of a Watch version of its app but declined to provide a reason as to why one hasn't arrived yet.

Responding to a query from Mashable, a Facebook representative avoided offering a timeline for the arrival of a Watch app from the social networking company.

"We're excited for the launch of the Apple Watch," the spokesperson stated. "We have nothing to announce today, but we're always evaluating new platforms to build the best Facebook experience for people."

What makes the absence of a Facebook Watch app especially intriguing is the fact that one has appeared in Apple's presentations of its smartwatch.

While it is unclear what is holding up Facebook's Watch app, Apple has given a reason for the absence of new fart and burp apps. It already has as many as it can stand, according to a letter sent from Apple to the developer of Fart Watch.

"We noticed that your Apple Watch app is primarily a fart app," stated a copy of the letter obtained by Cult of Mac. "We do not accept fart apps on Apple Watch."

The letter cites several of Apple's guidelines for developers, revealing that fart apps are not the only ones the company is no longer accepting. Overstocked and blacklisted Watch apps fall into the categories of fart, burp, Kama Sutra and flashlight.

Some could perceive the decision as Apple being an App Store tyrant, but Apple products and the company's online market place are beloved by many for the company's discernment.

If there are innovative ways to trigger burp and fart sound effects on an Apple Watch, then maybe Apple will open its heart to more of the novelty apps.

On the subject of things that may annoy Apple, members on an unofficial Android blog just happened to find an interesting Easter egg on the Apple Watch's launch day.

Tucked inside Google Maps was an image of Google's Android mascot taking a whizz on Apple's logo. The image has since been removed and a Google spokesperson told Mashable that graphic was likely submitted by an unaffiliated Android enthusiast.

"Even though edits are moderated, occasionally the odd inaccurate or cheeky edit may slip through our system," the spokesperson stated. "We've been made aware of the issue and are working on getting it removed."