Theory:

Strictly speaking MACD is a (as defined by Gerald Appel, who invented it) difference of fast and slow EMA and then a signal line (which is also EMA) is calculated for such a difference.

This version:

This indicator is not using EMA for MACD calculation but is using range weighted average (published here : Range Weighted Average with some more explanation) and is using range weighted average for signal line too (making it a sort of "all range weighted average" MACD).

Usage:

You can use it in all the usual ways how MACD indicators are used, Color changes added on MACD to signal line crosses and OSMA is displayed as a filled zone in order to facilitate the reading of the MACD.