Two things before the list, because they change what you should install.
Shopify has absorbed a lot of what used to be apps. Search and discovery with semantic search, forms, inbox, bundles, marketplace connections, basic subscriptions — these are native and free on paid plans now. Stores pay monthly for apps that duplicate features already sitting unused in their admin. Check the native option first, every time.
Every app has a speed cost. Most apps inject scripts into your storefront, and page weight is a conversion input. An app that lifts conversion 2% and costs you 400ms of load time may be net negative and you'd never know. This is why "what's the best app for X" is usually the wrong question. The right one is: what problem do I have, what would this replace, and is it worth the weight.
What follows is organised by category rather than ranked, because a ranking that ignores your revenue stage, catalog size and order profile is marketing. I've named the options merchants commonly run in each category and linked the expert pages for them. Where we have a deeper comparison guide, it's linked — use those for the actual pick.
App pricing and feature sets change constantly and most vendors price by order volume or list size. Treat category descriptions as durable and confirm current pricing directly.
