Shopify SEO: What's the best app for CSV uploading meta titles and descriptions in bulk?

Hey guys - I'm tired of uploading page and product metas one by one. I have 500 products/pages. What's the best (preferably free) way to upload them in bulk with a csv? I'd like to just fill out all the info on a csv and then upload it, instead of having to click each individual page and product and set them individually.