It works really well, and the image quality is good (my photos are too bright, sorry). I have not had many problems with the app too, it just some times do not save your new additions in your program list, even if they are still there in the app, but you can just add the gif/image again until it works.
For anyone having trouble in finding new image/gifs to add (as the app have good but scarce gifs) you can download the divoom app (it has many gifs created by users, made for devices like this one), download its gifs to your phone and add it through the ipixel app.