"Soundcool OSC" is a mobile app specifically developed to allow collaborative music creation with the Soundcool system. Soundcool (soundcool.org) is a free system for music education based on collaborative creation using smartphones, tablets, Kinect and computers, created by the Group of Performing Arts and Technology based at the Universitat Politècnica de València (Spain). Soundcool consists of a set of very simple modules, such as players, effects, VST hosts for virtual instruments or effects, keyboards, record modules, direct input sound modules for real time audio processing, etc. The different modules can be interconnected to allow very flexible music creations and sound transformations, being at the same time a system very easy to use. All modules run on a Windows or Mac computer and they can be controlled with smartphones and tablets via Wifi, or Kinect from Xbox. Soundcool OSC is a free mobile app for controlling wirelessly the Soundcool modules running in the computer. This application does not produce sound by itself. It just sends Open Sound Control messages (OSC) over a wifi local area network (LAN) where a central computer with loudspeakers receives the messages that control the soundcool modules. The Soundcool system is designed to perform colaborative music creations with several smartphones or tablets. To install Soundcool and create your own musical compositions see the project website www.soundcool.org (Downloads and Tutorials). For watching example videos and pictures see the the youtube channel, flickr and instagram links therein (www.youtube.com/c/soundcoolproject, www.flickr.com/photos/soundcool_project/, www.instagram.com/soundcoolproject/)