BetterHandles is a plug-in for Adobe Illustrator that combines a tool and palette to make working with Bezier curve handles easier and more powerful.

If you work with curves in Illustrator, you need BetterHandles:
1. Select multiple handles, and collectively move, extend, rotate, or retract them
2. Extend or retract handles without changing their angles
3. Copy and paste handles
4. Edit points numerically: anchor, in handle, out handle
5. Convert multiple points from corner to smooth or vice versa
6. Automatically extend new handles on multiple points
7. Intuitively reshape path segments, optionally constraining handle directions
8. Use slow-drag to divide the cursor movement for extremely precise moves
9. Equalize a point's handles
10. Add points to multiple curves at their horizontal and/or vertical tangencies
11. Split multiple paths at one or more points
12. Close multiple open paths, retaining endpoint handles or not
13. Remove one or more points, keeping the curve as close to the original as possible
14. Work with connector points (transitions between straight and curved segments)
15. Remove all redundant points on multiple paths
16. Snap to handles, points, or paths clearly and easily - without having to use Smart Guides

The license of this software is Free Trial Software, the price is $29.00, you can free download and get a free trial.