PDF annotators are very important to students who use tablets for school. These apps allow you to download and annotate documents. For example, many students download lecture notes with their PDF annotator apps and take all their notes from lectures using their PDF annotator app. These apps are an excellent tool for getting the most out of lectures, even more so than is possible with traditional paper notes. Also, most (if not all) of these annotators interface with Canvas allowing you to download files directly from Canvas to the PDF annotator. Many of them will even convert powerpoint files into PDFs making them much smaller thereby taking up far less space on your iPad.

There are several very good PDF annotator apps, each with its own strengths and weaknesses. Below are brief reviews of the top-ranked PDF annotator apps with links to additional outside reviews. This is not an exhaustive list and each person has their own favorite annotator app. We will add to this list as new features become available in existing apps and new apps come out.

iAnnotate (Provided by the School of Medicine)

This is definitely the highest rated and thus our most highly recommended PDF annotation app. It has outstanding built-in annotation, drawing, and navigation tools. You can open a variety of file types on iAnnotate (including .doc, .ppt, image files, and of course .pdf) and you can search for terms and keywords within these documents and your annotations. You can also add bookmarks to your documents. It is easy to share your files on iAnnotate with others or your cloud drive accounts. The apps annotation features include adding notes, drawing, highlighting, underlining, typewriter, stamp, straight-line, note, photo, voice recording, date stamp, and strikethrough. Many different colors are available for your text additions and highlighting. You can even copy and paste annotations within and between documents. One of the best features of iAnnotate is how easy it is to customize the app to your liking. For example, you can edit the number of toolbars, their size, transparency, location, and command buttons. When you transfer files from iAnnotate, you choose if you want your annotations to be transferred with the file or not. One downside of iAnnotate (as well as most PDF editors except GoodReader) is that it will sometimes combine words in annotations when a PDF is exported. If you simply use iAnnotate to edit and then view your files for studying, this will not be a problem for you. See reviews of iAnnotate here and here.

iAnnotate will be provided by the School of Medicine. Students in the iPad program will receive an e-mail with further information before classes start.

GoodReader ($6.99)

This document reader and annotator is strong in terms of diversity of documents it can open and compatibility with cloud storage sites. It does a great job of handling even large files (>100 mb) with ease. It is the best PDF annotator in terms of exporting annotated PDFs without altering the annotations (some apps combine words, which isn’t a huge deal for most people, but it’s good to be aware of this issue). Some of it’s features include highlight, underline, squiggly underline, strikeout, free text, free handwriting, bubble notes, 2-way sync with Dropbox, bookmarks for navigation, horizontal and vertical (but not continuous) scrolling, search within document, cropping, easy access to undo button, tabs for displaying different files at the same time, and annotation extractor that allows you to extract just your annotations from a file without the file itself. A new version just came out in May (2014) that allows users to alter PDFs by adding or subtracting pages. This is a great tool for students since it can make creating study guides very easy. Read some excellent reviews of this app here and here. Also, a review of the new upgrade to the app is here. Download the app here.

Notability ($1.99)

Some people absolutely love Notability. It is a very feature rich app and it makes taking notes (in the absence of a PDF to annotate on) very easy. It is built with students in mind. One of our favorite features of this app is the ability to record audio and link it with specific annotations or notes. So, when you’re reviewing a lecture, you can simply click on a note you wrote or a highlight you made and hear exactly what was being said at that point in time. This app has most, if not all, of the features of iAnnotate and GoodReader like highlighting, underlining, typing, hand writing, recording, strikethrough, palm rest (to protect against making inadvertent marks where you rest your palm on the screen), copy and paste annotations,  bold, italics, bullets, font presets, cursor controls, etc. You can also add pictures, web clips, figures, and drawings to your notes. Organizing and sharing files on this app is simple. It’s also a very reasonably priced app so consider giving it a try! In-depth reviews of the features of Notability are here and here. Download the app here.

PDF Expert 5 ($4.99)

Another favorite. This is, once again, a very feature-rich app that some people believe is superior to some desktop softwares. You can easily fill out forms, annotate PDFs with highlights, handwriting, insert text and stamps, and sign documents with this app. You can also merge PDFs and add or delete pages from PDFs with this app.  See the following reviews for in-depth discussions of this outstanding app here and here. Download the app here.

Adobe Reader (Free)

A very functional PDF reader that can display a range of PDF documents, including those with fillable forms, password protected files, and those protected with Adobe LiveCycle DRM. Adobe Reader has a search feature as well as bookmark and hyperlink support. The app processes the document in real-time instead of loading it entirely, so expect some blurred text when zooming in and out. Annotations are easy to insert and view. Callouts and doodles can also be drawn on documents. You can also add text and strike-through existing text. A short review of Adobe Reader can be found here. Download the app here.

Foxit Mobile PDF (Free)

This is a solid PDF reader app. Foxit can open normal and password protected PDFs, with support for document and user bookmarks. Various view modes can be used including Single and Continuous Paging, Thumbnail view and text-reflow. You can easily highlight, underline, or strikethrough text and add text boxes. Annotation colors, opacity, border thickness and note appearance are easy to adjust. Foxit has great Cloud support (e.g. total integration with Dropbox, SkyDrive, Google Drive, Box, and KuaiPan). Overall, it has excellent features. See a review of it here. Download the app here.

Evernote (Free; Premium version $5/mo)

This is an excellent note taking app that make it very easy to be organized. It has a very powerful search functions that searches notes, files, annotations, and even pictures. It is easy to annotate PDFs in this app, though it isn’t as rich in features as many of the other PDF annotation apps. Learn more here. Download the app here.