Power Apps can be used to build three different types of apps: portal apps, model-driven apps, and canvas apps. It has various licensing plans for different usage scenarios and includes daily API limits per user. Delegation support, which allows retrieving large datasets efficiently, depends on the data source and functions used. When building apps, developers should minimize network traffic, use components and galleries efficiently, and start planning governance. Power Apps is a versatile tool beyond just building mobile apps on SharePoint lists.