Filestyper allows you to change the Type, Creator, Created/Modified Date and Time as well as system flags e.g. Locked, isAlias, hasCustomIcon etc.
Classic Macintosh files have a Filetype (File) and Creator Signature(Creator). These are 4 characters each and may contain alphanumerics and some special characters. Together they identify a file so that an application knows if it can open it and if so, exactly what kind of file it should expect.
A file that is a Macintosh application (executable) will have a Type : AAPL. The author will have created a Creator signature which could be something like Bk04.
A file that is meant to be opened by a normal Macintosh application (not executed itself) will have a Filetype that corresponds to the Creator of the application. If Creator "Bk04" has an application that can read and save files, those files may have a Type Bk04.
filetyper_5.0.1.sit (474.4 KiB / 485.79 KB)
System 6.x - Mac OS 9 / compressed w/ Stuffit
FileTyper_5.3.1.sit_.hqx (788.6 KiB / 807.52 KB)
/ BinHex'd, use Stuffit Expander
filetyper-551.sit (637.88 KiB / 653.19 KB)
/ compressed w/ Stuffit
Emulating this? It should run fine under: Basilisk II