It is easy to focus on the Apps and what they can do but what is really essential is the functionality afforded by those Apps. The emphasis needs to be on the functionality and not the App - the verb and not the noun (researching not Google, note taking not Word. presenting not PowerPoint). Apps that perform a range of functions represent better value.

So for the iPad to be a constructive, effective learning tool what would be the basic set of Apps needed for :

Annotating - for drawing or annotating over images use SketchBook Express (Free). If you need to annotate over PDF files then the highly featured Good Reader ($5.49) is the premier app for this.

Audio Recording - for taking brief audio notes Audio Memo (Free) is one of many free tools available, for larger and higher quality recordings GarageBand($5.49) has excellent podcasting features to record and share audio, to match audio recordings with written notes use SoundNote ($5.49) or Notability ($4.99)

Calculating - MyScript Calculator (Free) is a calculator with an important difference. Write what you want to know and the question and answer are presented in a number sentence form. Very useful for further number investigation.

Drawing - for basic drawing SketchBook Express would satisfy the average person's needs. For those with real artistic needs then the more featured SketchBook Pro ($1.99) would be a worthy option.

eBook Reading - it is hard to go past the well featured iBooks (Free) to organise eBooks, Text Books, and PDFs. It also has note making and highlighting functions.

Music Creation - GarageBand is a premier music app that is suitable for all users from novice to expert.

Note Taking - best for short notations, Notes (installed) looks just like a notebook and performs this function well. For note taking plus the added feature of audio recording consider either SoundNote or Notability.

Photographing - the iPad is well set up with a forward and rear facing Camera (installed) that can take still images and video clips. Photo Booth (installed) distorts images to create unusual effects. The content of any screen can be captured as an image. All of this image content is stored in Photos (installed) where it can be edited and imported into other programs.

Organising - events can be recorded in Calendar (installed) and viewed in daily, weekly, monthly, yearly or as one continual list. Alerts can be set and appointments can be repeated. Events can also be synched with other devices through iCloud or an Exchange server. Keep organised by synchronise ideas, lists and notes across all your devices with Evernote (Free).

Presenting - for building PowerPoint style presentations Keynote ($10.49) is an excellent app. Haiku Deck (free) is a very scaled down Powerpoint alternative but is most likely all that is needed. Explain Everything ($2.99) can be used to create interactive lessons and tutorials.

Publishing - not the most featured but Book Creator for iPad ($5.49) offers very flexible layouts and supports text, images and audio content. Books created can be exported as eBooks and viewed in iBooks.

Researching - online information is easily accessible through Safari (installed) which has all the features of a computer web browser. Apps such as Wikipanion (Free) directly search Wikipedia and presents the information in an easy to read format.

Sharing - created content may be exported and shared in a variety of ways: a basic feature of all apps is the ability to email material, many apps support exporting to popular social network sites, Dropbox (Free) allows the sharing of content between devices or multiple users, AirPlay (Installed) allows wireless screen sharing with an Apple TV.

Video Editing - there are several options but iMovie ($5.49) has many features and is quite simple to use. Will export in HD quality.

Word Processing - on an iPad writing options are fairly basic but Pages ($10.49) can do most of the functions that are really necessary. Templates, text options, images, charts and more. Files can be exported in Pages. PDF or Word format. A basic option is Textilus (Free) which is not much more that a typing tool or Google Drive (Free) adds colour but needs Internet connectivity.