Earlier this year I reviewed PDFpen for iPad, and it remains one of my favorite tools for editing and annotating PDF files on the iPad because it has a great interface and is relatively easy to use, but it also packs in tons of sophisticated features. About two weeks ago, Smile Software released PDFpen for iPhone. The company sent me a free review copy of this $5 app to try out, and I'm very impressed. Editing PDF files on the iPhone is obviously harder than on an iPad because of the smaller screen (although PDFpen for iPhone does take advantage of the larger screen on the iPhone 5), but if you are on the go and only have access to your iPhone, this app can be incredibly useful and includes (as far as I can tell) all of the features of the iPad app.
The main screen of the app shows your documents as thumbnail images, and you can sort by either date or name. If you enable iCloud sync, then every document in your Documents folder is automatically synced with PDFpen on your iPad (and on your Mac if you use that software too, but I don't so I wasn't able to test that). Since I already use PDFpen on my iPad, that meant that when I first started using PDFpen for iPhone, all of my documents were there waiting for me. I can edit a document on the iPhone, and then a few seconds later the edited document is there on my iPad. Very sleek. Or if you want to create a new document, just tap the plus sign at the top left. You have several choices, including creating a blank document or copying a file from popular cloud services.
Once you open up a document, you'll see a toolbar at the top, or you can tap once in the middle of the screen to make the toolbar disappear so that you can use the entire screen to view the PDF file.
All of the editing tools that I described for PDFpen for iPad are here. Thus, you can draw on a document, add shapes, underline, etc. Once again, highlighting is handled very well. You can highlight a document even if it isn't a "readable" document with text, and highlighted words are not painted over with a opaque yellow box like some other apps do, but instead the black text stays dark black even when highlighted after you press the "Done" button.
Swipe left or right to move between pages. There are two ways to see other pages in the document. First, you can tap the grid icon in the toolbar at the top, which gives you the option to see and edit multiple pages (such as delete a page, move pages around, rotate pages). Second, if you swipe in from the left side of the screen, a bar pops up with thumbnail images of pages. Just swipe up or down to find the page you want and then tap to jump straight there.
PDFpen for iPhone includes the powerful Library feature. Just tap the library icon to add text boxes, comments, notes, shapes, photos from your Photo library, annotation marks, etc. There is also a powerful custom library where you can add an object to easily use that object again in the future. For example, in my PDFpen for iPad review I showed you that I made a custom exhibit sticker. Although you cannot automatically sync the custom library between the iPhone and iPad (that would be a great feature to add in the future), it was easy for me to create a new document on the iPad and add the exhibit sticker, wait a second for that file to sync to the iPhone, then select the exhibit sticker and add it to my custom library on the iPhone. Now I can easily paste an exhibit sticker on any document using my iPhone, and then using the text box function I can give the exhibit a number or letter.
This trick is also useful for storing your signature. You can use the scribble tool to sign a document with PDFpen for iPhone, but the iPhone screen is so small that it is difficult to get a good signature unless you have a very short name. But you can sign your name on a blank document in PDFpen for iPad on the large iPad screen, and then once that document syncs to the iPhone you can select the signature and add it to your custom library. Now, if someone ever emails you a document and asks for your signature, just open up the file in PDFpen on your iPhone, add your signature, and then email the file back.
I mentioned above that you can create a new document by copying it from any of the popular cloud document services, such as Dropbox. Additionally, PDFPen has the ability to sync with one of your Dropbox folders so that you always have instant access to your documents. (This feature was added to PDFpen for iPad after I wrote my review earlier this year.) After you choose a folder to sync, PDFpen for iPhone downloads and syncs in the future the names and dates of all files, but doesn't actually download the documents themselves until you tap a document. That helps to reduce sync times. After you edit a document in a Dropbox folder, within just a few seconds the edited file is available in your Dropbox folder on all devices that sync with your Dropbox. The only flaw I see with the implementation is that I don't yet see a way to tell PDFpen for iPhone that you no longer want to sync a Dropbox folder. I presume this will be fixed in the future.
There are a few features that I would love to see added to PDFpen for iPhone, such as the ability to search for text in a document, but I am amazed at all of the advanced features that this app does include. It even includes the ability to edit the text in a PDF file, assuming that the file is readable. So if you find a typo or other problem in a PDF file, you can fix it right on your iPhone without having to go back to Microsoft Word or whatever program created the document in the first place.
If you just want to view a PDF file on your iPhone, there are lots of free options available. My top recommendation is probably Apple's own iBooks app , which is the fastest PDF viewer I've seen on the iPhone. But if you want to go to the next level to annotate and edit PDF files on the iPhone, PDFpen for iPhone is a great option. It is a beautifully designed app that is full of sophisticated features. And if you already use PDFpen for iPad, then it is a no-brainer that you will want this app as well.