What are some alternatives?
When comparing GlooMaps and A1 Sitemap Generator, you can also consider the following products
WonderWebWare Sitemap Generator - Sitemap Generator is freeware program that will help you to automatically generate site maps for google, bing and yahoo in their respective file formats.
Screaming Frog SEO Spider - The Screaming Frog SEO Spider is a small desktop program (PC or Mac) which crawls websites’ links...
DYNO Mapper - Create Sitemaps with the DYNO Mapper Visual Sitemap Generator.
XML-Sitemaps.com - Free Online Google Sitemap Generator.
phpSitemapNG - phpSitemapNG is a free Google Sitemaps generator written in PHP, but also generates RSS-based...
XmlSitemapGenerator.org - Easily create HTML, RSS and XML Sitemaps online for free.