I use Pocketbitcoin which is similar, I looked into Relai, but privacy terms looked better in pocket, don't remember what now, relai also requires an app and an email to use it i think. So it was a matter of data privacy mainly on the app, I avoid apps, I also hate registrations when there is no reason to.
Discussion
Thank you, #[3]. For some reason, your message was hidden to me until now.
I don't think an email is necessary to use Relai, although an app itself is. The reason is simple, signing messages isn't something, newcomers understand and the app is doing all the work for them.
Anyway, a web version is currently worked on so hopefully it'll be a bit more private.