Downloading MagicSpeller for REALbasic 1.6.8 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The program is included in Developer Tools. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The actual developer of this software for Mac is infiniteline studios.
From the developer:
Magicspeller for Realbasic is a collection of a REALbasic objects for use within the REALbasic development environment. MagicSpeller allows you to use a dialog-based spell check system as well as an inline system that checks spelling as you type. Both options provide a customizable number of suggested corrections that are automatically prioritized to maximize accuracy.
You may want to check out more Mac applications, such as TreknoBabble, RegExr or iConStruct, which might be similar to MagicSpeller for REALbasic.