Web 2 brought interactivity to web pages and has progressed to the stage where it is now the a basic feature of most websites. It is therefore time for it to come of age and to just be referred to as the web and not as if it is still something new.

A lot of interactive web functionality was originally built on Flash which, for a variety of well documented reasons, does not not work on iPads, this created a lot of apprehension when the iPad was first released. But like all technology, the web has moved on with newer sites being developed in HTML 5 which does work on iPads. Some popular older sites are making the transition to work on mobile devices whilst some have created their own App. For those web sites that still do not work well on an iPad, there are no shortage of apps that will perform the same or similar function.

This is by no means a comprehensive list but it does cover the more popular sites commonly used in education. They are not merely websites to visit and browse but sites which have a level of interactivity and foster creative use.

Websites that work well on the iPad :

Answer Garden
A brainstorming or feedback tool that does a simple thing very well. Once the "garden" is created users go to the web address and leave words on the wall. Words grow in size if entered multiple times.
Childrens Books
Picture books by Hans Wilhelm, 10 books free to view online in their entirety for non commercial use. Would look great as a big book over an Apple TV or through an IWB.
Opens to a new cork board each time.! Bookmark the URL to access your notes or share the URL to create a collaborative working space that you can edit & see changes in real time. Works simply and well.
Create a Graph
Kid Zone site - contains five different graph and chart styles. Includes details instructions and the ability to save the created graph. Graph can be downloaded in a variety of formats to use in other applications.
For those needing a heavy duty math calculator this is a well featured online graphing calculator. The graphing uses a variety of colours and updates as the equations are changed.
Sign up for a free account and it's amazing how the avatar can reflect the creator. Once created the avatar can have many classroom uses.
A cool place for tweaking digital photographs. Choose an effect, add a photo and voila! Simple as that. Works well with the iPad photo library and camera. Save the finished image back to the iPad.
Egg Timer
A simple online countdown timer that ends with an audible tone. The beauty of this site is that the time can be made part of the URL so you go directly to a timer of your own setting.
Join the global community of teachers and students to connect with classrooms around the world for collaborative project based learning activities.
Listen to free music online - quite an amazing site with a large library of original songs. Legalities? As you are listening to music, not downloading it, it's OK, apparently the site is paying royalties. Simple and efficient interface.
Jigsaw Planet
Make a jigsaw from the images on the site or from the iPad photo library or take a photo with the iPad camera and turn it into an instant jigsaw puzzle. Great example of how a web site can integrate with the iPad.
A space where teachers and students can safely navigate the digital and increasingly social online landscape, Students are able to exercise digital citizenship within a secure, private classroom blogging space.
National Geographic
Access to a huge assortment of high quality video, photo and news resources with specific links to educational material and a kids fun section.
Used to be called Wallwisher. A collaborative space where invited users can add and organise thoughts and ideas on virtual sticky notes. Add links, text, images, documents and videos to the wall.
An online grammar checker and proof reading resource that provides students with an in depth analysis to help improve grammar and writing.
Poll Everywhere
Create open response or multiple answer question sets and online surveys. Create polls with an audience size of 40 for free. Polls can be answered from a phone, Twitter or web browser.
Curate links on a selected topic in a highly visual format. Allowed 3 Scoop.it topics per user account for free. A great way to present a list of links to students.
Create online flyers and posters, bit similar to Glogster. A good selection of templates and the ability to add text, images, video, audio and embed links. Save online or use your computer's print to pdf option.
Create an online story using a large variety of high quality themed images. Finished stories are stored and viewed online.
Survey Monkey
Easily create and distribute an online survey. You can have up to 10 questions and 100 respondents for free. The paid version has unlimited use and greater options.
Creates interactive timelines with popup dates (on a computer) that contain additional information and images when clicked on. On the iPad the timelines are viewed in a vertical table. Less visual appeal but still effective.
Allows multiple used to simultaneously work on a single document in real time with all users instantly able to view changes being made by others. Not yet perfect on the iPad but working well enough to be functional.
A real time back channel tool to collate comments, ask questions and get general feedback in a created "room" which can remain active from between 2 hours and one year. Comments are listed in most recent order.
Has had a name change to Padlet.
Be a collaborative author by creating digital books that contains text, images, and videos. Collaborative with others by inviting them to contribute to your books. Books in your profile which can be shared.
Wikis are a highly collaborative educational tool, Wikispaces has always been very supportive of the educational sector and is well used in schools and has a a fully functioning WYSIWYG editor.
Wolfram Alpha
The computational search engine works fine in its standard form on the iPad. They also have a mobile web version and several Apps but the original standard interface will be good enough for most people.
A family oriented site that nutures the inquisitive mind with daily Wonders such as 'How do Helicopters work?' and 'Why is it called Breakfast?'
Directs to a mobile version of the site which works slightly differently (better some would say) than the computer version. Many video creation apps have the facility to upload directly to YouTube.

Websites that now have an App :

Automated video making - add images and text, select some music and Animoto does the rest. The free version is limited and designed more for social than school use but still a useful App.
Was a suite of media editing tools. The photo editor has made it to the App Store as a free product with lots of add on packs available to purchase.
A secure community space where teachers and students can be connected and share information in a social media format. Perfect for posting and submitting material, collaborations and discussions.
Google has greatly improved its functionality on the iPad and continues to improve. Currently this app gives access to Google Search, History, Apps ( including Docs and Drive), Voice and Goggles.
Khan Academy
Access and download Khan Academy’s complete library of over 3,200 videos covering a large number of topics, including K-12 math, science topics such as biology, chemistry, physics, humanities, finance, history and more.
This first release of Mathletics Student includes only an initial selection of curriculum activities created especially for iPad. The team at Mathletics will be releasing more and more activities.
Organize and share topics of interest. Browse pinboards created by other people, select the Education category for resources shared by other educators. The web version works fine on the iPad but the App is free and looks great.
Prezi Viewer
Was originally only a viewer but now has limited editing functions. Text and images can be added and edited but they seem to be the only functions available - hopefully it will continue to improve.
Survey Monkey
A long time well regarded web based survey tool with a large user base. The app now allows users to create surveys and polls, send them to anyone, and monitor the results from the iPad.
Access to the entire library of over 1000 TED Talk videos from the world's most fascinating people. The web site also works fine but the app is less cluttered.
Create and share conversations around documents, snapshots, diagrams and videos -- basically anything there is to talk about. Talk, type, and draw right on the screen. Create up to 5 free VoiceThreads.

What doesn't work - usually still Flash based :

Bubbl.us- plenty of mind mapping Apps to choose from including an Inspiration and SimpleMind
Glogster - builds multimedia posters - Try Smore instead - A Glogster Edu app in under construction
Odosketch - use a variety of bushes and colours to create online masterpieces - Plenty of sketching Apps available
PhotoPeach - slideshow creator - Several slideshow Apps available
Picassohead- build an image using facial parts - Plenty of sketching Apps available
Pixlr - very different to the app, a powerful online image editor, similar to Photoshop - iPad has image editing options but not as good
Screenr - web based screen recorder - Try DispRecorder App
Tagxedo - turns words into images, requires Silverlight to work - Several options on the App Store, search for Word Cloud
Tutpup - maths and word challenges, a good site but plenty of Apps available for this purpose
Voki - create a speaking avatar - Talking Tom and many other similar apps are available
Wordle- creates word clouds, needs a Java plugin - Several options on the App Store, search for Word Cloud