Sigma is a universal browser for your favorite websites and social networks, allowing you to vote and comment on interesting topics of any kind and discuss with the community.
Platforms
- iPhone
- iPad



iChan has been discontinued. Similar apps include Sigma: Your Feeds United , which has a free version. Other options are anychans, Chance, KurobaEx and Kuroba. In total there are five Imageboards like iChan for Android, iPhone, iPad, self-hosting and the web.
Sigma is a universal browser for your favorite websites and social networks, allowing you to vote and comment on interesting topics of any kind and discuss with the community.


