PDFPen by Smile Software exists for both iPhone and iPad. This app allow you to work with PDFs on the go. Here are some functionality highlights of this handy app.
Fill out PDF forms on your iPhone or iPad. You can even sign your document using our finger or a saved signature. With this handy app, gone is the need to print out a form, fill it out, scan it and send it back.

Easily Manage PDF Files. You can email your documents, copy them to iTunes, Dropbox, Evernote, and more. You can also change the way your documents are sorted, such as by date or name. PDFPen allows you not only to manage your saved documents, you can also manage individual pages within your documents. For example, easily reorder your rotate the pages that make up your file. With third party integration, you can work on the road, save them and then work on the same document at your workstation.

Annotate your PDFs. Use highlighting, pen tools, text correction and more.

Navigate documents easily. When bookmarks have been used on a PDF, you can use your table of contents to easily access different parts of your document from your mobile device. You can also use the search tool within PDFPen to find what you’re looking for.

PDFPen will also allow you to add objects; import and export documents via email, Evernote, iTunes, Google Drive and more; synchronize your documents with iCloud and Dropbox and much more. We definitely recommend this app. It’s handy, easy to use, and cheap too!