ACTi has recently released the new version Moblie Explorer. 
Mobile Explorer Version: V2.1.10
New Features and Enhancements: 
            1.Megapixel IP camera can now be supported when video stream is viewed through NVR.
               The video stream from NVR to Mobile Explorer will be resized down based upon user settings.
                2.Support 2 way audio function.
                3.OSD on to edit device OSD configuration.

Limitation:
             1.PTZ operation can only operate on touch-screen devices. 
                If your mobile device does not support touch-screen,then you cannot operate PTZ operation.
             2. Pocket PC 2003 not supported
             3. Get video from device support MPEG4 only. Get video from NVR support MPEG4 and MJPEG.
             4. Audio out function only supported when getting video from NVR
             5. Max resolution limit 720x480
             6. System will automatically drop frame while overloaded. 

>>Mobile Explorer Download:Mobile Explorer V2.1.10 (3.07mb) / Release Note:Release Note