The developer of Fart Watch reached out to us to let us know that Apple had rejected his app, for the following reasons: 
 
 2.11 – Apps that duplicate Apps already in the App Store may be rejected, particularly if there are many of them, such as fart, burp, flashlight, and Kama Sutra Apps 8.1 – Apps must comply with all terms and conditions explained in the Guidelines for Using Apple Trademarks and Copyrights and the Apple Trademark List 2.11 Details We noticed that your Apple Watch app is primarily a fart app. Apple’s dislike for fart apps was disclosed through its rejection of the (creatively named) Fart Watch app, which did exactly what it says on the tin.
– Fart jokes are available on 3,000-year-old Sumerian stone tablets but apparently not on Apple's latest piece of 21st-century technology. The developer of Fart Watch, a whoopee cushion-inspired app that boasts it can "turn your Apple Watch and iPhone into a remote-controlled fart machine," tells Cult of Mac that Apple told him it had been rejected, because the company noticed it "is primarily a fart app" and "we do not accept fart apps on Apple Watch." It appears that fart apps go against the "sophisticated, elegant image" Apple wants for the watch, writes Chris Mills at Gizmodo, but it's "probably just a matter of time until someone jailbreaks the Watch, and sideloading galore can begin." (A French inventor says he can make farts smell like roses—or chocolate.)