There are several possibilities, which probably won’t match your needs:
- Since last month it’s possible to test apps on a device without the need of a paid membership.
- There’s a possibility to deploy an app through a service like TestFlight, but this needs either a profile installed on the device (like HockeyApp) or always new build since the old ones expire after 30 days.
- You could deploy an app with the Enterprise Program
The easy way you describe is not possible.