Among various, I think one of the best and affordable is Foxit PDF Editor. Very lightweight, almost as Foxit Reader, ideal for comments to a document from which we don’t have the base or responsibility, as it is the case with the Publishing House that is using Adobe In Design CS to Mac, and that only generate the pdf.
Practically recognizes any object, image, figure and, in the case of texts, groups them in horizontal lines separating styles when selecting.
In this case, I would like to make comments in an external Word document with detailed explanations, what I do is just switch to another color the content to be edited or make indicative figures.
Also it has interesting tools for this purpose, like group segments, ungroup and then selected the segment you can change its color, size, import source, etc.
Images and figures
You can add, replace, or insert new images. Both images and objects can be rotated in 90 degree sequences. Even the text can be worked. Between basic shapes it includes rectangles, ellipses, lines, polylines, curves and objects with gradients tones.
Once the changes have been made, we store them with the Save button. In case you don’t have a paid license, it creates a brand in a corner that says that it has been edited with Foxit PDF Editor.
Not so bad, so it’s time to download it, test it and make sure what you need in order to buy it. Among the most interesting features, you can import pages from other document indicating the range of pages and where you we want to insert it.
Here you can download Foxit PDF Editor; on the same page you can see other solutions from the same company, including a developer’s kit (SDK) and one where it can be made forms in pdf.