The Nikon WU-1a Wi-Fi adapter allows you to connect your Nikon camera to your phone or tablet. This way you can easily shoot self-portraits and share photos. To use it you have to download (free) Wireless Mobile Adapter Utility from the Google Play Store. The adapter is automatically powered by your camera, so you do not have to recharge it.
Please note that the adapter is only suitable for the following cameras: Nikon 1 S2, Df, D7100, D5200, D3200, D3300, COOLPIX A, P7800, P520, P530, P330.