Do you use PDF files or read documents in PDF format? Even if you don’t use them regularly, I’m sure that you’ve come across a PDF file or two in your lifetime. They’ve been around for over 20 years and can contain links, buttons, form fields, videos, audio and more.

Reading PDF files can be done in many applications, but a lot of those apps don’t include annotation tools. In this post we’re going to focus on apps that do allow you to annotate PDF files. Whether you want to add text notes, bookmark a section, highlight or underline text, these free tools will allow you to do just that.

Shortcut to PDF annotation tools for:

• iPhone/iPad
• Android devices
• Browsers

Read Also: Top Web Annotation And Markup Tools

iPhone/iPad

Adobe Reader

This is the official Adobe Reader mobile application which works for the iPhone and iPad. It can also be used to fill out forms and electronically sign documents. With it, you can: highlight, strikethrough, underline, draw (freehand), comment (sticky notes) and add text using the typewriter tool.

PDF-Notes free for iPad

This is the free version of the premium app pdf-notes; it’s available for the iPad only. Along with support for AirPrint, you can annotate your PDF files using a variety of pens, highlighters and text notes. It includes smooth finger writing and a palm rest so that there are no accidental marks on your documents.

AnnotDoc Lite

AnnotDoc is unique because it is the only iPad app that allows you to annotate Microsoft Word and PowerPoint files, on top of PDF files. You can also use it for highlighting, underling, watermarking, handwriting and adding signatures. The Lite version, however, does not support saving or exporting your documents, but you can take screenshots of your annotations.

PDF Review Free

This is the free (try before you buy) version of PDF Review available for both the iPhone and iPad. The app allows you to leave feedback and notes on PDF documents. It helps simplify the review process of any file or document and allow feedback from multiple users. All feedback can be merged into a single list and you can even generate structured reports.

UPAD Lite

UPAD Lite is an advanced note-taking application with annotation features. You can handwrite notes, highlight text, add sticky notes and reference images. UPAD uses smooth retina ink, which results in beautiful, detailed handwriting. You can export any type of document as a PDF or PNG file by email or to cloud services like Dropbox, Evernote and Google Drive.

Mendeley

Mendeley is a companion app to the desktop tool for Windows. You’ll get your own digital library so that you can read, annotate and organize all types of files including PDF. Mendeley includes many features such as citation and bibliography generation, sticky notes and highlighting, importing and organizing PDF files, collaboration with a team, and much more.

PDF Max

The free version of PDF Max is great for annotating, filling in forms and taking notes. At this time, it’s the only iOS PDF application that supports Adobe’s Rich Text Format Typewriters (aka FreeText). You can annotate by highlighting, underlining, crossing out and using "squiggly tools." It also supports addition of comments and threaded conversations, great for collaboration.

DocAS Lite

The free version of DocAS lets you annotate PDF files, sketch ideas, create presentations, record audio clips and share notes. You can also access documents anywhere: PC/Mac desktop (via wifi), Dropbox, Box, Google Drive, FTP, WebDAV, other iOS apps and more. As well as PDF files, DocAS supports Microsoft Office and Apple iWork files, RTF, text and photos.

Android

Adobe Reader

Just like Adobe Reader for iOS, the Android version lets you view, annotate, comment, fill out, electronically sign and share documents. It has all of the same features as the iOS app like freehand drawing, highlighting, underlining, etc.

iAnnotate PDF

It’s very surprising that iAnnotate PDF for Android is free, especially since the iOS version is $9.99. You can open multiple PDFs using tabs, search through your documents and share them. iAnnotate PDF also supports Box OneCloud, which allows you to open files directly from and/or save them back to Box.

Qiqqa

Qiqqa is a research tool, much like Mendeley (see above). This is a companion app to the desktop tool [Windows], which lets you read and annotate your PDF files. With Qiqqa for Android you get: continuous scrolling, pinch-to-zoom, full-text search, annotations, bookmarks, tagging, cloud syncing, annotation reports, reference citing etc.

PDF Annotation

With a long press anywhere on your PDF document, you can add annotations. With PDF Annotation, you can also view a separate list of your annotations for easy reference. Although there is not much information provided about the app, a few user reviews suggest that it’s a bit restricted such as having no way to draw directly on the text or highlight.

Mantano Ebook Reader Lite

Mantano is actually an eBook reader, but it includes annotation tools. You can use it to download eBooks from the OPDS catalogs and add your own catalogs. When it comes to annotations, you can: add text notes, highlight, share quotes and add bookmarks. By using Montano Cloud (paid subscription), you can backup your annotations and sync between devices.

qPDF Notes Demo

Although this is only a demo of qPDF Notes, it includes all features available in the full version; however, a watermark will be added to your PDF files if exported – which is fine for personal use or trying before you buy. With qPDF Notes you can add text, sticky notes and shapes to your PDF files. You can also highlight, cross out, underline, and sign documents.

SmarQ Reader

Here is another PDF reader with annotation tools as well as page-cropping and sharing. There’s a built-in file manager for organizing and syncing your documents. You can add comments and highlights to PDF files in different colors and even pen sizes. There’s also a document manipulation tools for adjusting the brightness, inverting colors, adding texture and more.

Web/Browser

Need annotation tools that work on the Web? Try these on for size.

A.nnotate

A.nnotate is great for those wanting to annotate images, PDF files and Microsoft Office documents online. With it, you can add text notes, highlights and strikethrough. The collaboration feature with threaded comments and the ability to add tags to notes, makes A.nnotate great for freelancers, small teams and even businesses.

PDFescape

PDFescape is not only great for editing and annotating PDF documents, but you can also create new PDF forms, fill out PDF forms, password protect your files and share documents. With PDFescape, you can add text comments, shapes, images, sticky notes, and highlights to documents. Check out many other advanced features PDFescape has.

GroupDocs

GroupDocs is an advanced document collaboration tool that includes annotation features for PDF and Microsoft Office documents. You can add comments and mark up your text in real-time, much like documents in Google Drive. GroupDocs has 3 paid plans, and a free 14-day trial plan that lets you try before you buy.

PDFOnlineReader

PDFOnlineReader is not just for reading PDF files online. You can also add annotations, add hyperlinks and bookmarks, and highlight text. It’s a lot simpler to use and it’s great for those who want to annotate quickly, save and download their files. It also offers PDF desktop products for batch PDF creation and converting PDF files to other formats (and vice versa).

Crocodoc

This online document viewer lets you upload and annotate PDF files, Microsoft Office documents and images. With Crocodoc you can add text comments and drawings, highlight, and strikeout text on your documents. You can also use it to fill out PDF forms, collaborate in real-time and much more.

What do you use?

Now that we have shared 20 free PDF annotation tools for iOS, Android and the Web, it’s your turn. Do you use a free or paid PDF annotation tool? Which tool do you use and for which platform?

Want to learn more about PDFs? Read our Mastering PDF: 80 Free Tools, Tips and Resources.

iTunes – media library, music player, app organizer and the place to go when you want to sync your apps with your iDevices – has recently seen its 11th update, with plenty of improvements and new features. Some of these features include a smarter, more organized browsing experience, preview history, personalized recommendations and Facebook integration.

The new update makes iTunes a pretty powerful app but also a very complicated one, so it’s a good idea to pick up some shortcuts, tips and tricks to help you navigate through iTunes faster and better.

Read Also: How To Enable Half-Star Rating In ITunes

iTunes 11 Keyboard Shortcuts

We are fans of shortcuts and the trend doesn’t stop at iTunes. Here are some of the shortcuts you can use to breeze through the site.

Shortcuts	Description
Command + ,	Preferences…
Command + H	Hide iTunes
Command+ Option + H	Hide Others
Command + Q	Quit iTunes
Command + N	Playlist
Option + Command + N	Smart Playlist…
Command + W	Close Window
Command + O	Add to Library…
Command + U	Open Stream…
Command + P	Print…
Command + I	Get Info
Shift + Command + R	Show in Finder
Command + Z	Undo
Shift + Command + Z	Redo
Command + X	Cut
Command + C	Copy
Command + V	Paste
Delete	Delete
Command + A	Select All
Shift + Command + A	Select None
Fn + Fn	Start Dictation…
Option + Command + T	Special Characters…
Command + J	View Options…
Command + B	Show Column Browser
Option + Command + U	Show Up Next
Command + /	Show Status Bar
Command + F	Search
Command + T	Show Visualizer
Control + Command + F	Enter Full Screen
Space	Play
Command + .	Stop
Command + →	Next
Command + ←	Previous
Command + L	Go to Current Song
Control + Shift + Command + →	Next Chapter
Control + Shift + Command + ←	Previous Chapter
Command + ↑	Increase Volume
Command + ↓	Decrease Volume
Command + E	Eject Disc
Command + [	Back
Command + ]	Forward
Shift + Command + H	Home
Command + R	Reload Page
Command + M	Minimize
Option + Command + 1	iTunes
Option + Command + 2	Equalizer
Option + Command + 3	MiniPlayer
Option + Command + M	Switch from/to MiniPlayer
Enter	Play the Currently Selected Song from the Beginning
Command + 1	Open "Music"
Command + 2	Open "Movies"
Command + 3	Open "TV"
Command + 4	Open "Shows"
Command + 5	Open "Podcasts"
Command + 6	Open "Books"
Command + 7	Open "Apps"

Tips / Tricks to Get The most Out of iTunes 11

Here’s where we share with you some of the simple tricks to help you with iTunes. If you have more to add, just drop it in the comments section.

#1. Use the Remote App on iPod touch, iPhone, or iPad to control your iTunes library from a distance. The Remote app is available in App Store for free.

#2. From anywhere in iTunes, start a search in the iTunes Store by typing something in the Search field and press Option + Return.

#3. Press Option + Delete to delete the selected playlist and all the songs it contains from your library.

#4. Press Command + Delete to delete the selected playlist without confirming that you want to delete it.

#5. Press Option + Command + → or ← to move forword or backword within a song.

#6. You can use the 2-finger swipe gesture to navigate back and forth between pages in iTunes Store.

#7. Keep MiniPlayer on top of all other Windows by ticking the option in Preferences > Advanced.

#8. When a song is selected, press Option + Return to add current song to "Up Next" queue.

#9. Press Option + Command + S to bring back the static sidebar.

#10. Press Shift + Command + L to search the selected item in Google.

Adding background image with CSS is nothing new, this feature has been there since its inception. But we were limited to only add one image in one declaration block. Now, CSS3 is raising the stakes by proiding you the option of adding multiple backgrounds.

How to use it?

In the old days, when we need to add more than one background image, we most likely will interrupt the HTML structure as well as add more classes to achieve the desired result through CSS, something like this.

  .overcast1 {  	background-image: url("images/overcast.png");  	background-position: 150px 25px;  }  .rainbow {  	background-image: url("images/rainbow.png");  	background-position: 200px 10px;  }  .overcast2 {  	background-image: url("images/overcast.png");  	background-position: 250px 25px;  }  .sunny {  	background-image: url("images/sunny.png");  	background-position: 100px 10px;	  }  

The code above is clearly superfluous. In CSS3, this code can be concatenated in single background-image property, as follows;

  .weather {    width: 500px;    height: 280px;    margin: 50px auto;    background-image: url("images/overcast.png"),  			  url("images/rainbow.png"),   			  url("images/overcast.png"),   			  url("images/sunny.png");    background-position: 150px 25px,   			  200px 10px,   			  250px 25px,   			  100px 10px;    background-repeat: no-repeat;  }  

In this code, we have added the same four images with different positions in accordance, producing this stunning results.

• View Demo

Adding Animation Effect

Furthermore, we can make the result even more stunning by adding CSS3 Animations. To make the coding simpler, we are going to use only the standard syntax from W3C, but remember that the browsers – IE9, Firefox, Opera, Chrome, and Safari – still need their respective prefixes for this to work.

Recommended Reading: Creating Advanced “Marquee” With CSS3 Animation

  @keyframes weather {     0% {      background-position: 120px 25px, 200px 10px, 280px 25px, 80px 10px;    }    100% {      background-position: 150px 25px, 200px 10px, 250px 25px, 100px 10px;    }  }  

Once we have specified the @keyframes, then we only need to add the animation with the keyframe name to the intended selector, in this case .weather;

  .weather {    animation: weather 5s;  }  

That’s it, we can now see the animation effect in action from the links below as well as download the source for further examination.s

• View Demo
• Download Source

Browser Supports

According to CanIUse.com, CSS3 Multiple Backgrounds is already supported in the following browsers; IE9+, Firefox 3.6+. No luck with Internet Explorer 8. But if you can assure yourself that you can leave IE8 behind, you can use CSS3 Multiple Backgrounds right now.

Further References

• Using CSS Multiple Backgrounds – MDN
• CSS3 background Module 3 – W3.org