Make sure you updated your camera to the latest firmware. The trial app will not start after one day, which is not a bug. Please do no post bad review because your camera is not supported- I cannot support them. Most larger DSLRs will do, most smaller models will not be compatible, or not with all features. Use the one day free trial to test if the app is working fine with your camera. The alternative selection by thumbnail in the app might show un-rotated thumbs with black border in some cameras. The app just picks up the list you selected in the Nikons Wifi menu (see app web page or your cameras manual for details). Please mention: it is fastest to select the images to download in your camera. You can also synchronize your Nikon cameras time from your device. Great for quickly sharing photos on the go via mobile, or for selfies. You can also remotely trigger the shutter release button, just like with an IR remote. Alternatively you can select the photos to download using a simple thumbnail overview. Wirelessly download images you marked as 'Send to smart device' on your WIFI (not Bluetooth) capable Nikon DSLR camera. Use the one day free trial to test yours before buying. P900, D500 and crippled Snapbridge models do NOT work for sure. *** Primarily DSLRs supported! (Nikon D-xxxx WITHOUT Snapbridge) *** A few Coolpix models and other Nikon compacts like Nikon 1 may also work.