You need an USB OTG cable for connecting your camera to your phone.
Not all phones/tablets are compatible. You need at least 4.x Android or higher with USB host support.
For more information check:
This app is free with no ads so please don't add negative comments just because you ROM don't have the required USB support.
And no it's not only the kernel that needs to have USB support but your Android to. Some of Android 2.3.x have the required USB support but not all, so before you give a negative comment at least check if your ROM supports USB devices (USB accessory support is not enough)
Constructive comments are welcome.
Change camera properties,
Browse images on camera,
Transfer images from camera to Android device,
Preview images (jpg and raw),
Live view histogram,
Manual focus movement while in live view,
Start movie recording (only on camera models that support it),
Custom bracketing (up to 9 images),
Time-lapse (simple and advanced with control file and ability to move focus and send commands to Arduino),
Sound initiated capture (with spectral display and frequency/intensity selector,
Nikon flash commander dialog (CLS) for easy settings (only on camera models that support it),
Custom profiles for camera properties, custom bracketing, focus stacking, flash commander
Remote control over wireless network (Android devices must be on same network)
Support for WU-1a/1b adapter (PTP/IP)
LRTimelapse help screen - read more about it at https://code.google.com/p/dslrdashboard/wiki/lrtimelapse