title: Launch my iPhone app on device through instruments
body: <p>An app I've created is already installed on my device that I simply want to launch using instruments.  It is already installed on my device.  I simply want to launch the app.  I am using this</p>
  
  <p><code>instruments -w &lt;device_id&gt; -t "/Applications/Xcode.app/Contents/Applications/Instruments.app/Contents/Resources/templates/Activity Monitor.tracetemplate" -D /tmp/ignoredtracedata.trace &lt;app_name&gt;</code></p>
  
  <p>This is what I get</p>
  
  <p><code>Instruments Trace Error : (null)</code></p>
  
  <p>I had this working at one point.  Then without making any changes the next day I came to work on it and it wasn't working <code>:(</code>.  I've tried things for a couple of hours and heven't made much progress.</p>
  
  <p>I am using the Ruby gem Frank to run tests.  I'd like to launch the app in different languages which is why I want to use instruments instead of simply adding the <code>-d</code> debug flag to launch the app on the device.</p>
  
  <p>Does anyone have anything that will help me?</p>