A2X - A2X automates ecommerce accounting for Shopify, Amazon, Etsy, Walmart and eBay sellers worldwide. Trusted by hundreds of leading ecommerce accounting firms.
FileProInfo - It's All About Files, Software, Online Tools - 100% Free
Jungle Scout - Amazon product research made easy.
File-Extensions.org - Large computer file extension library with detailed explanation of each file type with links to download free or associated software programs.
Helium 10 - Our software contains multiple Amazon seller tools to help you find high ranking keywords, identify trends, spy on competitors, & optimize product listings.
FileInfo.com - FileInfo is the central file extensions registry and contains a database of over 10,000 file types.