This tool converts Arabic script Unicode block text into Arabic Presentation Forms-B text so that the letters look all connected and in the right order even in environments that do not support LTR layout / IMFI letter shapes.
About "reverse letter order": Since this reordering only reverses the text, when the text spans multiple lines (whether or not line-breaks are in the text data), the lines will be in reverse order. In such cases I recommend you that you do the reversal line by line.