New features of Simple XML sitemap
Version 2.10 of Simple XML sitemap is mainly a feature release with only a few minor bugs fixed. The new features are
the implementation of the changefreq parameter
the ability to set an interval at which to regenerate the sitemap
the ability to customize XML output
the ability to add arbitrary links to the sitemap
image indexation
See the 8.x-2.10 release page for details.
Source: New feed