Here is a growing list of apps (including optimized sites and web apps) for the iPod Touch and the iPhone that are useful for learning, performance support or productivity purposes.  Apps are listed in alphabetical order.  (If you know of an app useful for learning or productivity, email me at jane.hart@c4lpt.co.uk or tweet me @c4lpt)

General apps

1. 30Boxes Calendar - allows you to easily manage and share your upcoming events and follow your friends online.

2. Approver.com iPhone Edition - makes it easy to view document review and approval status from your iPhone or iPod Touch

3. BBC iPlayer - view BBC programmes for up to 7 days

4. Digg iPhone Application - a way to discover and share Digg content for the iTouch

5. EditGrid Spreadsheets - EditGrid offers one of the leading online spreadsheet experiences that now includes support for your iPhone

6. Educate - application designed to support teaching professionals in schools, colleges and universities

7. Evernote for iPhone/iPod Touch lets you capture any moment or idea as it happens, wherever you may find yourself

8. ezMemorize  - allows you to add notecards and categorize them and share card sets with others

9. Facebook - for your iPod Touch or iPhone

10. Feed Reader - RSS news feed reader especially optimized to read full text feeds like an eBook.

11. Glide - Sync with your desktop to view Powerpoint and Word docs on your iTouch

12. gMail - for the iPhone and iPod Touch

13. Google Calendar Mobile - your Google Calendar schedule from anywhere on your iPhone or iPhone or iPod Touch.

14. Google Docs Mobile - View your documents from anywhere on your iPhone or iPod Touch

15. Google Notebook Mobile version -

16. Google Reader - for the iPhone or iPod Touch

17. GradePad - manage groups, create assessments, track performance

18. hahlo.com - iPhone-styled interface for Twitter

19. Instapaper - Save long text content for later (designed for the iPhone)

20. iPheed - private to do list which you can formulate on your computer and easily retrieve on iPhone or iPod Touch

21. iPhone ruler - turn your iPhone or iPod touch into a ruler

22. iPhone Typing Test - Test your typing speed

23. iPod Touch Photo application for Facebook - view your photo albums in Facebook

24. iQuizshare - fun quiz for iPhone or iPod touch

25. iTranslator - Translate from and into 5 different languages: Dutch, English, French, German, Spanish

26. iTunesU - Delivers 24/7 access to educational content from hundreds of top colleges, universities, and educationally focused organizations.

27. iTW - a TiddlyWiki for the iPhone/iTouch - It is a plain TiddlyWiki with the look and feel of an iPhone application. It works also fine in Safari.

28. iWPHone Wordpress Plugin and Theme - automatically reformats your blog’s content for optimized viewing on Apple’s iPhone and iPod touch.

29. iZoho - iPhone Office

30. Jajah - Voice calling from your PC.  Also works with iPhone

31. Jott - voice communication via the iPhone

32. Listingly - combines the power of your desktop computer and your iphone or mobile to create a best-of-both worlds list builder

33. MindBites - mobile version of the instructional video site

34. Mobile SMEStorage - Access your stored files from your iPhone

35. Mobile Web Docs - Create documents and save them on the web

36. Moblle Zoho  - Documents, spreadsheets and presentations on your iTouch

37. Netvibes Mobile - Brings the power of the Netvibes personalized homepage to your phone.

38. NewsGator Mobile - RSS news reader

39. Nozbe - Simply get things done - an iPhone-friendly interface for the Nozbe web-based application that simply helps you get things done.

40. Omnifocus - OmniFocus on your iPhone or iPod touch. Synchronized with your Mac via MobileMe or WebDAV.

41. OpenClip - cut and paste on the iPhone

42. PayPal - send and receive money online from your iPhone/iPod Touch

43. PicoWiki - a hosted wiki for the iTouch and iPhone

44. PogoNotes - PogoNotes will help you remember those random thoughts you get throughout the day, as well as to store important information

45. Quibblo - take quizzes on your iPod

46. Quizzler - quizzes on the iPod, created with Quizzler Pro

47. RoamBi - Turn your own data into dynamic visualizations for the iPhone

48. Remember the Milk - the popular task management service is now optimized for iPhone and iPod touch

49. RSS Player by Waxor - read RSS feeds on your iPhone or iPod touch.

50. SeeFile - Online storage site designed for your iPhone

51. Schmap - City guides and local search of the iPhone and iPod Touch

52. SimpleReader Mobile - online news feed reader with an interface designed especially for the iPhone and the iPod touch

53. Siri - virtual personal assistant for the iPhone

54. SME Scheduler - An automated meeting scheduler and manager providing

55. Smub - Post, share and bookmark instantly from your mobile, bookmarklet available for iPhone

56. SpeedyMarks - Makes it easy to open and to create visual bookmarks of your favourite web sites on the iPhone. It uses screenshots to show a preview of the stored web sites.

57. Springlets - Quick search bookmarklets for the home screen for commonly searched sites like Wikipedia, IMDB, etc.

58. Tetris - play the game on your iPhone or iPod Touch

59. TextonPhone - More than 30,000 books and novels viewable on your iPhone and iPod for free!

60. Toodledo - single place where all your to-dos are permanently stored and easily accessible

61. Tweety - iPhone/iPod Twitter app

62. Twitter for iPhone - iPhone/iPod Twitter app

63. TypePad for iPhone - now features a new iPhone-optimized interface for updating your weblog

64. Typing Tutor for iPhone and iPod Touch - Increase your touch screen typing speed on your free time and track your progress all for free

65. UniDo - Universal Notes Manager

66. Ustream iPhone viewer - watch and chat with any Ustream show directly from your iPhone

67. webChattr - Live Chat Rooms are the first and only chat rooms fully-optimized for the iPhone. The interface looks great, is responsive, and chatting even works speedy over EDGE! Rooms are easy to create instantly and can be bookmarked straight to the Home Screen.

68. Wifi Touchpad - wireless keyboard/mouse for a presentation

69. Wikipedia - lets you easily read, search and browse Wikipedia articles right on your iPhone or iPod Touch.

70. Wordpress for iPhone blogging application

71. Zensify - lifestreaming app for the iPhone that lets you easily update, discover and keep track of what's important to you across multiple networks

72. Zumobi - blends Facebook, Twitter, Flickr, and YouTube - plus your favourite web content

Subject specific apps

1. iConjugator! - Conjugate your verbs in 5 languages (Dutch, English, French, German and Spanish)

2. iPocketBible - Read and study the Bible on your iPhone or iPod Touch

3. Word of the Day - Presents you with a new word to add to your vocabulary. Along with the WOTD, you get the definition, synonyms and example usage