OD E-Channel Modifier allows you to modify enveloped values without having to go to the Graph Editor. It is a generic Layout Plugin:
Options:
Accessible Envelopes : This shows you which envelopes exist and can be selected to be modified
< : Goto previous keyframe
> : Gto next keyframe
+ : Create Key
- : Delete Key
C : Copy Key
P : Paste Key
Open: Opens the envelope in the Graph Editor
Curve: shows which type of curve the selected Key has
Tension: Sets the Tension of a key on a TCB Curve
Continuity: Sets the Continuity of a key on a TCB Curve
Bias: Sets the Bias of a key on a TCB Curve
Here's a how-to video showing OD E-Channel Modifier in action.