OMEGA is easy-to-use and available for SPSS and SAS. In addition to calculating omega and alpha, it generates all possible subscales of at least three items from an additive scale containing k items. For each subscale, it generates omega (or alpha) and displays various information about that subscale (such as the subscale-full scale correlation). Summary statistics of individual items and the full scale are also generated. For a full description of OMEGA and its features, read the documentation in the download folder.
In addition to the syntax version for SPSS users, there is a dialog box based on the graphical user interface (GUI). Not all options are available, but the dialog box can be permanently installed and used for simple estimation.