I am looking for a program that can annotate, tag and .pdf files. Essentially I want to use my iPad for document review where I can input documents and highlight certain parts. Also, if I find something in particular, it would be nice to be able to add a "tag" to that page so that I can search for it and easily find it later. Does anyone know of an app that is capable of this? The ability to export and/or share with a PC Program would be ideal while maintaining all the highlights and tags that I will be creating so that I can view them from my work desktop as well. Thanks.