Handwrite / draw on a text document
I think what you're looking for is usually called "freehand drawing". I can't find any app that supports free hand drawing on Word document. However, Adobe Reader for Android supports freehand drawing annotation on PDF document. You can convert your word documents to PDF and use Adobe Reader to make your annotations.

Freehand annotation on an editable document like Word generally makes little sense anyway, because it's not always obvious where the annotation should move to when the text is edited.