Indie Hackers Stacks is a directory of indie products with their software stacks. You can use it to discover the tools that other makers use to build their products. Publish your own stack and get free exposure and some SEO juice.

Self-Hosted Software List is a directory of the top self-hosted solutions in various categories. List there if you're working on a product that the users can host themselves. Submitting your products to Self-Hosted Software List is free.