Some of the tidbits I have contributed to the world of Squeak can be found in http://www.charm.net/~arning/. Highlights are listed below, but you may want to browse the directory directly in case there is a later version not reflected in this page. Most are compatible with whatever version was current when the tidbit was posted. I cannot promise to keep them all updated as Squeak continues to evolve. Most recently updated files are listed first.
SyntaxMorph (2.8) offers a graphical view of Squeak method syntax. Version 2 includes debugger support for SyntaxMorph as an alternate to the standard code pane. Featuring: balloon text to show the value of variables as the mouse passes over them. http://www.charm.net/~arning/SyntaxMorph.09Jun1827.cs
SqMailServer (2.8) is an experiment in sharing an email archive. With such a tool, the entire Squeak email archive could be available in anyone's image. Messages could be classified automatically as they are received or users could add their own classifications. http://www.charm.net/~arning/SqMailServer.24Apr1833.cs
EekMail (2.5) is an email client that I have been using for almost 2 years now. While this is an old version, it may be of interest. Included is a hierarchical list for viewing the contents of mail folders. http://www.charm.net/~arning/eekMail.15Jun523pm.cs
Source Comparison Browser (2.5 - requires change set 1358) is a tool for comparing two squeak source files side-by-side. Hierarchical lists, color coding, etc. Updated for unpleasant side-effect of changeset 1375. http://www.charm.net/~arning/Comparison.18Aug114pm.cs
ObjectExplorer (2.4) Included in Squeak since version 2.5 (change set 1358) offers a hierarchical alternative to #inspect. Nice when you need to dig deep and don't want a lot of windows opened. http://www.charm.net/~arning/ObjectExplorer.21Jun359pm.cs
MandelBob (2.4) paints Mandelbrot sets. It implements the interesting (though I cannot prove it correct) Mariani-Silver algorithm. New version features: increased speed, varying picture sizes, save to disk and save as desktop background. http://www.charm.net/~arning/MandelBob.17Jun431pm.cs
BobsBrowser (2.4) is an experimental code browser featuring a central code pane with various ancillary windows/menus for navigation. One key feature is the use of hierarchical lists for delving into classes/methods/etc. http://www.charm.net/~arning/BobsBrowser.14Apr1206pm.cs.txt