An iOS version is in progress and should be released in the next few months [1].

The TextSecure servers are not hosted in Google's data centers. Google's GCM push messaging framework is used to deliver messages to Android users, but the GCM payloads are fully encrypted.

[1] https://github.com/WhisperSystems/TextSecure-iOS

I know it's in progress. I'm anxiously waiting. If you tell me where I can send $ or BTC to help it go faster, I'll gladly oblige.

See [1] for donating BTC and [2] for donating other currencies through the Freedom of the Press Foundation.

[1] https://whispersystems.org/blog/bithub/

[2] https://pressfreedomfoundation.org/

I'd actually like a Chrome browser extension version, too (yes, I recognize the vulnerabilities vs. a true native client, but signed browser extensions mitigate a lot of those)

This is already in progress [1].

[1] https://github.com/TheBlueMatt/textsecure-chrome