[ur-whale]

Thanks for the link, but is that the only place Tether "lives"?

Last I read up on it, it was implemented on top of Omni [1]

[1] https://hackernoon.com/a-closer-look-at-tethers-blockchain-5...

Are there multiple Blockchains where Tether was issued?

[bouncycastle]

Tether is issued on multiple blockchains. Omni is Bitcoin based, and recently most of it moved from Omni to Ethereum ($12.6 bil). Others include Tron ($6.4 bil), EOS ($90 mil), Liquid ($16.5 mil), and so on.

Full stats https://wallet.tether.to/transparency