Free SSH GUI client with ssh tunnel support for Yosemite?

Is there any free SSH GUI client for Mac OSX? Coming from Windows I would be happy with something as simple as Putty.

Features:

1. Free


2. Connection Manager


3. SSH tunnel support


4. Yosemite ready (and retina pretty)


5. Currently active (development not dead)


6. Support for private key authentication

I'm aware of similar questions posted here but I haven't found a good alternative covering both 2) 3) 4) and 5) requirements...