What is the benefit of shipping apps over shopify's built in shipping module?

[VanyaRagul]

Hi There,

What is the benefit of shipping apps over Shopify's built in shipping module? Am confused about whether I should use Shopify's inbuilt shipping calculator or get an app for this. I haven't managed to find any serious shipping discounts with Shopify calculated rates of in that of any other apps.

I haven't started selling yet. Just building my website at the moment. I intend to sell small, handmade household items that weigh less than 500 g. And I want to charge a flat fee for standard shipping and provide options with carrier calculated charges for priority shipping in case the customer wants it.