Updating existing forms created in InfoPath, Nintex or Custom built Forms to PowerApps.
Customizing list views and creating mobile apps for smartphones, tablets and other devices.
PowerApps might be a powerful tool for you Power Users. After proper education and training users would be able to create new forms and apps by themselves and share them with other team members or employees.
After months of extending the functionality of PowerApps Microsoft finally can provide a powerful tool to work with data. A lot of connectors available in PowerApps (and SQL is one of those) which makes it more flexible and powerful for application development. You might also found it as a useful tool for power users. And taking in mind Microsoft continue working on extending and improving the functionality - PowerApps might become a pretty good solution for enterprise needs.