The error message is saying that the static library libechoprint-codegen-ios.a hasn't been built for the i386 architecture - which is the architecture used by the simulator.
You can find out which architectures the static library has been built for by running the following code in Terminal:
lipo -info ~/Documents/Instajam/libechoprint-codegen-ios.a
It will likely tell you it is built for armv7 and armv7s. That will support all but the oldest iOS devices at the time of writing.
You could build libechoprint-codegen-ios.a to run on a simulator. Here's a good stackoverflow post if you are interested in doing that: Build fat static library (device + simulator) using Xcode and SDK 4+
The easiest option would be to just plug your phone in and not worry about building a fat static library. :D