When to go for a native mobile app:
1. The application requires high graphics performance or native capabilities like accelerometer, Bluetooth, camera, gyroscope etc.
2. The application has to interface with other native applications or features of the mobile devices like contact list, calendar etc.
3. The application required video and audio capabilities.
4. The company wants to reach out to prospective customers via the various app stores and take advantage of their sales channels.
5. The application can be run offline.
Follow this link for more help-
http://www.infosysblogs.com/engineering-software/2011/05/native_mobile_apps_or_mobile_w.html