Love what hedgehog is doing! However, we are cross-platform and never expose the users master private keys to the developer. When a user logs in to an app, only the app specific key pair is delivered on auth.
Yes! This is one of the top things on our priority list. We will be completely removing the need for passwords and switch to one time use passwords and 2FA.
You can sign up for our slack on our website and we'll keep you updated :)
We've been moving fast trying to get SimpleID in as many hands as possible, but we absolutely want to support other blockchains. More in-depth Ethereum support is next up, then we want to look at adding support for blockchains like EOS, Steem, and more. It'd be great to get feedback from others on what blockchains to support!
Let me know if you have any other questions :)