Scanner Pro is an app that I have been meaning to check out for a long time because several lawyers have told me that it is their favorite app for using an iPhone to scan documents. I just bought the app last night and I can see why so many people love it. Normally I like to wait a week or more before I write a review of an app to have ample time to try it out, but I am posting this review today because Readdle is celebrating its fifth birthday right now by discounting its apps. If you buy Readdle apps before the end of the day on August 2, there is a huge discount: $1.99 instead of the normal price of $6.99. And all of the other Readdle apps are on sale too, so for example you can get PDF Expert (which I reviewed three months ago) for only $4.99 instead of the normal $9.99.
Scanner Pro lets you scan a document and then converts it into a PDF file. I presume that you can use any iPhone or the third generation iPad to take the picture, but to get the best quality picture you're going to want to use an iPhone 4S with its improved 8 megapixel camera, and that's what I used for my tests. It works best if you place the document against a darker background. Alternatively, if you already have an image of a document on your iPhone, you can use an image that you already have.
After you get a picture of the document, the app automatically tries to straighten the image. In my tests, it often does a great job on its own. However, if you want to tweak it, the app has fantastic tools for doing so. Just drag each of the four blue dots to a corner of the page. Of course, you cannot see what is under your finger as you are doing so, so the app helpfully provides a zoomed image to the side so that you can move the blue dot to just the right place. After you are finished adjusting all four sides (or after you are satisfied with what the app did on its own), click the Next button.
Next, the app automatically adjusts the black text and the white background of the page to make the text on the page as sharp as possible. In my tests, what the app did automatically was great, but if you want to adjust the contrast or the brightness, tap the top left button to do so. And if you need to rotate the image, the button at the top right lets you do that.
After you tap save, you are finished with the first page of your scan. If the document has multiple pages, just go through the prior steps again to add more pages.
Once you have all of the pages, there are a few things you can do. The button at the bottom left lets you send the scanned document as a PDF attached to an e-mail. The button at the bottom right gives you many more options including print, fax (for a fee), upload to services such as Google Docs, or open the PDF file in another app on your iPhone.
But you might not need to choose any of those options because of two built-in cloud storage options that are very helpful. First, if you use the Dropbox service, you have the option to have the app automatically upload every scan to a folder called "ScannerPro" in your Dropbox. (This also works with Evernote.) I love this option because it lets you take a scan, do the quick adjustments, and then you are done. The document will be in your Dropbox folder on your computer (and on your iPhone, iPad, etc.) whenever you need to access it. So for example, you can scan receipts when you are on a trip and then they will automatically go to your Dropbox folder so that they are all waiting for you on your computer when your trip is done.
Second, you can use iCloud to automatically share documents with Scanner Pro on your iPad. (This is a universal app, so you can just pay for it once and then use it on both your iPhone and your iPad.) This lets you use the better camera on the iPhone 4S to scan a document, but then use the larger screen on your iPad to review the document.
As you can see from that picture of the iPad app, the scans are kept in the app itself. Thus, even if you don't send your scans to Dropbox or someplace else, you can always go back to the Scanner Pro app to review your scans. You can also create folders to hold multiple documents.
The quality of the scan is quite good. It is not as good as you would get with a real, stand-alone scanner, but it is more than good enough to read and share a document. I created a sample document and then used Scanner Pro on my iPhone 4S to scan it, and here is a link to the PDF file that the app created if you want to see the results for yourself.
Note that Scanner Pro only creates an image of a document; it does not OCR the document to make the text searchable.
If you want to use your iPhone or iPad to turn paper into PDF, Scanner Pro is a great way to do it. Although it takes a few steps create the PDF, each of these steps works very well and is very fast.