Well, ordered one to go with my new 7100. I have started taking more landscapes, and instead of a flippy screen, i thought the ability to use my phone screen would be a good alternative, especially while the camera is sat low on a tripod and you don't want to move the camera to check the result.
All i can say that the android app that accompanies the wu1a is a buggy, featureless, pile of poo.
Constantly loses wifi connection, very slow to operate, the live view takes 15-30s to refresh, clicking the shutter button has similar lag. Total lack of features, no ability to control shutter, aperture, focus, white balance that i can see. No option to download low quality jpeg to speed things up. The app force closes. No documentation. Do you want to view the pictures you have taken, well you wait while the app downloads thumbnails of ALL the pictures first. Then the app closes 70% through download, you have to start over again. When you do get to see the thumbnails, you have to click one by one to select the ones you want to download. Download of 5 nef files took 3 minutes, when the phone screen went to sleep, the download was lost. So i tried again with just one picture, touching the screen regularly to make sure it didn't sleep. I then had a message 'download complete'. So what can i do with the file once downloaded - adjust exposure, crop, align, white balance. Nope, nothing. Just share or delete.