.IWM File Extension
File TypeiWriteMusic Data File
What is an IWM file?
An IWM file is a data file created by iWriteMusic, a music notation app for iOS. It contains music notation information for a composition in the proprietary iWriteMusic (IWM) format.
IWM files are created when a user saves a composition with iWriteMusic. The file type allows users to save compositions, close them, then re-open them at a later time for further editing.
You can only open IWM files with iWriteMusic. If you receive an IWM file from an iWriteMusic user, ask them to instead export the composition as a .MIDI file, which is more widely supported.