i developed the app in android.which was run in lollipop device but crash on kitkat device.i am new to android.Please help me for find the solution? :         apply plugin: 'com.android.application'

        android {
        compileSdkVersion 19
        buildToolsVersion '21.1.1'
        defaultConfig {
        applicationId "com.example.itsoft37.kitkat"
        minSdkVersion 11
        targetSdkVersion 19
        }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'),         'proguard-rules.txt'
        }
    }
        }

        dependencies {
            compile fileTree(dir: 'libs', include: ['*.jar'])
            compile 'com.android.support:appcompat-v7:19.1.0'
        }

i am new to android.please help me for find the solution
the error shows unfortunately stopped on device..


