Hi Kevin,
Another couple of other free options are:
MuniPack – https://c-munipack.sourceforge.net/
MetroPSF – https://github.com/blackhaz/MetroPSF
The advantage of these is they can produce output files of the photometry ready for uploading to the BAA Photometry Database. If you ultimately wish to submit to the BAA database then that is a distinct advantage. You can also do this with AstroImageJ and AIP4Win, though you have to use these in combination with the BAA Photometry Spreadsheet and that requires an Excel license.
Cheers,
Andy