The ruler, which allows you to easily measure one point on a chart to another. The dev team could develop ruler tool native into Amibroker.
@MMC227 if you are asking this as a question (don't see any question mark) - it is already built in - take trendline and join point A to Point B and hover your cursor- you will have all the information
I understand using a trend line we can get this information, but it is not a ruler tool.
It is ruler tool too. WHEN YOU ARE DRAWING, it displays CURRENT, updated in REAL-TIME measurement in the STATUS BAR.
@MMC227 don't forget about an Arrow Tool:
... but as Tomasz wrote above, if you enable Status Bar (View --> Toolbars ---> Status Bar)) you will see all readings live when drawing:
All this tools will be very helpful.