The following procedure also works for getting other tools:
1. Open Celtx with any project or create a new one (what we just did earlier).
2. Click on the menu option Tools, then Toolbox.
3. A new dialog box appears. Click on the Get Celtx Tools button at its bottom.
4. This opens the Celtx Special Offers page. Click on Dictionaries in the left column.
5. A page for spellcheck Dictionaries opens, as shown in the following screenshot:
6. Click on the dictionary you want. You will be asked by the application to download the file (Celtx should be open on your computer). The dictionary will download and appear in your toolbox (the dialog box you opened). You can select more dictionaries at this time or exit and restart Celtx to begin using the dictionary that we just downloaded.