This replaces one of the wooden LinnStrument sides with a holder that keeps an iPad in place at a comfortable angle. It accommodates all iPad sizes from the first model to the latest Air, including some iPhones (I tried the 5 and the 6+). Since the LinnStrument can be bus-powered from all iOS devices with a lightning connector, this is a really nice standalone expressive music-making combo.
The holder didn't work with some headphone plugs when using an iPad Air. Made some updates to fix this.
Just print it, support is included, remove the red sections from the screenshots. It fits on the UltiMaker 2's build platform by rotating the middle section 45 degrees.
Then slide the sides on the middle and screw it onto the LinnStrument's back instead of the wooden side. You can use the same screws, but I didn't use the washer of the middle screw since it sticks out a but too much then, possibly scuffing the iPad.