Signal is an encrypted messaging app for smartphones and desktops that I and a lot of other folks use on a daily basis to communicate with discretion and security. I like it so much that I've moved away from using other services on my iOS and Android phones to using Signal for all of the texting I do, even with those who don't use the app. Unfortunately, according to The Verge, the Signal team is having a difficult time trying to provide its services to users in the UAE, Egypt and Oman, where the app has been banned by the government. Considering the fact that these states aren't known for treating political dissidents and minorities none too well, that's a big deal. For some people, encrypted comms are essential to avoiding incarceration or worse.
The crux of Signal's issues with providing services to users in these countries is that Amazon, whose CloudFront web services Signal's parent company, Open Whisper System, uses, has banned domain-fronting. Domain-fronting, put simply, is a technique for making traffic from one site look like it's from another site. In an email received by Open Whisper System's founder, Moxie Marlinspike (best damn name in the business,) the General Manager of Amazon CloudFront called Open Whisper Systems' domain-fronting out, telling Marlinspike that Amazon would love to have their business, but not his company refuses to comply with their no domain-fronting policies.
When access to Signal was originally censored in Egypt, Oman, Qatar, and UAE, we responded by through Google App Engine. This meant that to block Signal, those countries would also have to block google.com. That was not a step those countries were willing to take, and as a result Signal has been usable there for the past 1.5 years, even though direct access remains blocked. This required no configuration from users; they could simply install the app and use it as normal.
For the time being, not being able to offer Signal to users via domain-fronting in countries where the government clamps down hard on privacy could be a serious threat to anyone living there with a proclivity for partaking in anything outside of regime-enforced societal norms. Given that Open Whisper Systems has already moved on from using Google's servers to provide Signal's services to their users, the company is running out of ground to stand on. They're looking for a work around that will allow Signal users in countries where the app is banned to continue using it, but for the time being, people in Oman, the UAE and Egypt are shit out of luck.