WhaleVault, which originally began as a fork of Steem Keychain, is a Chrome / Firefox extension that can perform all these functions and more natively, while also simultaneously supporting all the well-known graphene-based chains (Hive, Steem, Blurt, Whaleshares, Bitshares, EOS, etc).

For example, you can use it to login to Hive as easily as Steem, Blurt, or Whaleshares.

The functions let you easily sign and/or transmit transactions, encrypt/decrypt memos, and more!

https://hive.blog/steem/@alexpmorris/whalevault-secure-graphene-cross-chain-key-store-extension