The app takes the pleasant experience of building Lego and turns it aggravating. The colors are off, it doesn't highlight what pieces are being added unless you zoom way in, it's hard to see the lines between pieces, the box showing what piece is next sometimes overlays the main diagram and you have to close it, there are no measurements on sticks, and you have sit through these annoying animations when you finish a part. Give me my PDFs back!!! There is no PFD for 910016. I checked.