ScoreCloud Express: This is a free application on PC and mobile device, which can convert humming, whistling or musical instrument performance into electronic music score. The application can automatically identify all kinds of notes, and also provides editing and sharing tools.
HumOn: This is an application specially designed for iOS and Android devices. It can convert your humming audio into MIDI files. It can be used to record and store your music creation and allow you to share your work with others.
Melody scanner: This is an online application that can convert humming recordings into music scores or MIDI files. It can automatically recognize melody, rhythm and chord, and provide a variety of instrument options.
Please note that these applications may not be able to perfectly convert recordings into music scores or MIDI files, but they can provide a basic starting point and make it easier for you to turn ideas into music.