InstaCalc offers an intuitive conversion tool, several rate calculators, a BMI calculator, and a programming calculator. These calculators are similar to mini-spreadsheets. They are user-friendly and do not require that you adhere to a strict calculation syntax to get an answer. You can share your calculations with a link. And teachers can use the embed code to add a calculator on their class website or online assignment for use by their students.

This free image editing webware lets students redesign photos and pictures they upload, and add a variety of special effects.  The free version interfaces with Facebook, Flickr, MySpace, Phanfare, Photobucket, Picasa, Smugmug and Yahoo.  Students can add text and borders, as well as touchups and special effects.  There is no printing capability.

LearningReviews note: This webware is somewhat dated. Although many of the interfaces such as MySpace and and Picasa are obsolete, there are still some very useful features on Fotoflexer that you don’t see on freeware. Foremost among these is the ability to layer photos and set transparency levels of layers. You have the ability to hotlink images. There are many interesting special effects. And you have the ability to edit and download an image without logging in, which is useful with younger students who cannot set up accounts on their own.

GeoGebra is a free award-winning downloadable software program and apps that combine geometry, algebra, spreadsheets, statistics and calculus. For example, you can use it for geometry to construct objects from points, vectors, segments, lines, and conic sections, and then use functions to change the objects dynamically. Use it to find derivatives and integrals of functions and it offers commands like Root or Vertex.

There is extensive documentation on the software, a large community of users, online forum, and many online videos to assist you. Click the Team link on the site to see examples of Geogebra in action. And there’s a growing collection of app versions of many of its components, including a graphing calculator, for iPad/iPhone and Android devices.

Audacity is a free downloadable audio editor and recorder, compatible with for Windows, Mac OS X, GNU/Linux and other operating systems. Use it to record live audio, podcasts, convert tapes and records into digital recordings or CDs, and edit Ogg Vorbis, MP3, WAV or AIFF sound files. You can cut, copy, splice or mix sounds together, or change the speed or pitch of a recording.

This support community for this software is extensive, and the site has detailed documentation and tutorials, with many more on Youtube and Vimeo.

Flickr is a free tool that lets students and teachers upload, organize and share their photos online.  You have the ability to limit who has access to your images. Free registration via a Yahoo account is required.

Flickr is also available as an app for iPad/iPhone and Android devices.