I don't know if this is the right place to be, but this is definitely related to SEO.
Big e-commerce like Amazon uses this meta tags for their SEO, specific to bookselling category: (Product name | Author | ISBN | Site URL | Product type)
Most of the apps on Shopify don't describe a feature to add custom metafields.
Is there any way / any app that I miss that can pull this off guys?
You can easily bulk edit your Shopify store's metafields from Mixtable's Google Sheet-like spreadsheet interface. Map all the metafields you want to columns, update the relevant cells, and sync the data back to Shopify. Shopify stores SEO data as metafields as well. You can also set your Shopify SEO metafields based on other metafield values by using a formula.
As much as I want to go talk about this, MixTable did not even respond since the last time you commented.
So I don't know what to follow up on here.
@tinooze That's a great idea to get the data you want into meta descriptions.
Checkout https://apps.shopify.com/airpower for an easy way to manage the metafields that you want to achieve this. With the data in metafields, then you'll need to edit your theme.liquid file to compile the title/meta descriptions how you want for product pages.