Twitter Tongues gives some great insight into something not widely documented. Districts with different languages are somewhat known, but Twitter Tongues presents them very clear visual way. Twitter Tongues might just be one of the most accurate endeavours into mapping the niche-spatiality of spoken languages.
Compared to tweets from world capitals like London and New York, it would be interesting to see how smaller cities fare with this kind of data visualization. Perhaps there are some hidden ‘Chinatowns’ out there that Twitter Tongues could visualize for us!