Xero connects to a very large ecosystem of third-party apps — stock, ecommerce, job management, expenses, industry-specific tools — and it is the largest of the main packages. Whether you need one depends entirely on whether your trade has a workflow the core product does not model. An ecommerce seller usually does, because reconciling platform payouts to orders by hand is miserable and an app does it automatically. A landlord with four properties usually does not; tracking categories cover it. Our advice is to start without and add only when a real, recurring pain justifies it, because every app is another subscription, another connection to break, and another thing to re-authorise. The businesses that struggle are the ones that bought six apps at setup and use two.