From Zoltan Hubai:
With DslrDashboard you can control you Nikon DSLR or any other PTP compatible camera.
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.
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.
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)