https://arstechnica.com/information-technology/2018/01/apple-rejects-app-that-claims-to-detect-net-neutrality-violations/

An iPhone application that attempts to detect whether ISPs are throttling online services was rejected by Apple when its developer tried to get it into the company's App Store.

David Choffnes, a Northeastern University professor who researches distributed systems and networking, built an app called "Wehe" that tests the speeds of YouTube, Amazon, NBCSports, Netflix, Skype, Spotify, and Vimeo. Abnormally low speed results for one or more of those services might, in theory, provide evidence that your mobile carrier is throttling a service.