JOSM plugin extending Improve Way Accuracy mode with helpers to place nodes at accurate distances and angles.
Go to preferences (F12) and make the following changes:
Keyboard shortcut change needs restart, after you will see a new icon on editing toolbar, similar to Improve Way Accuracy mode but greyscale.
Extended features appear when you press W second time.
These objects follow mouse in real time. If you press Alt+Ctrl, mouse position is ignored, extended helper objects use original nodes. The same display is available any time long-pressing W, even when other mode is active.
Windows key (also called meta, super, mod4) locks new position to the center of equal angle circle.
Original tool called "Improve Way Accuracy" was written by Alexander Kachkaev. Extended features were added by András Kolesár. Feedbacks are welcome.