Userify - Userify is a cloud-based SSH key management solution.
Persistent SSH - Persistent SSH is SSH tunnel manager for a Windows systems.
Ganymed SSH-2 - Ganymed SSH-2 for Java is a library which implements the SSH-2 protocol in pure Java.
MyEnTunnel - Basically, MyEnTunnel is an efficient method for maintaining the tunnels of TCP SSH, MyEnTunnel has many advantages upon its usage. Plink (PuTTY Link)...
FireSSH - After 13 years and 25 million downloads later, Firefox has officially removed FireFTP and FireSSH support from the browser. Thus, I've ended support / development of the addons. I recommend switching to Waterfox to continue using the addons.
Core Tunnel - Core Tunnel is the best way to manage your SSH tunnels, with OS X Keychain integration.