I also doesn't exist on non-gooogle play devices, because the author thinks that getting software from somewhere else than walled garden is "repeating the desktop mistake all over again" [1]

There might be iOS version, but there very likely never will be web version, or FxOS version or desktop version or anything like that.

Which is really sad, because unlike Telegram authors, TextSecure's author is very good with crypto.

[1]: it's a long read: https://github.com/WhisperSystems/TextSecure/issues/127