Up to now, any 4Chan-related app has been a taboo for Apple; 4Chan apps are immediately banned from the App Store due to “user-generated objectionable content.” Because of this, any 4Chan app for iPhone has to be installed through Cydia or sideloaded onto the device.
Luckily, once in a while, some 4Chan app falls through the cracks of App Store reviewers and gets approved. One lucky app that got passed through reviewers is Sigma. Sigma is a one-in-all app for social media. Through Sigma, you can browse your favorite social media website, including Reddit, 4Chan, HackerNews, and many others.
You can enjoy and download Sigma from the App Store for iPhone and iPad for free.
TheChan
The Chan was another 4Chan app for iOS that slipped through the App Store reviewers. The app even supported smooth .webm files playback. Unfortunately, Apple later found and removed the app from the App Store. However, if you’re familiar with sideloading apps onto your phone, you can still download The Chan app.
You can download The Chan .ipa file from GitHub.