i18n perhaps

F2-i18n.js

/** 
 * In Container, by Container Developer
 */
F2.init({
    i18n: {
        locale: 'fr-fr' //container-provided default for French, France
    }    
})

/** 
 * App Manifest, by App Developer
 */
{ 
    scripts:['/appclass.js'],    
    styles:[],     
    apps:[{
            data:{},
            html:'<p>My app</p>',
            i18n: {
                supported_locale: ['en-us','fr-fr']//default 1st
            }
    }]
}

/** 
 * AppClass.js, by App Developer
 */
var drawHeader = function(){
    return '<h1>' + i18n('My App Header') + '</h1>';
}

var i18n = function(str){
    
    var map = {
        'My App Header': { 
            fr: 'My App tête' 
        }
    }
    
    //Container defined F2.i18n.locale = 'fr-fr'...
    var currentLang = F2.i18n.locale.split('-')[0] || appConfig.defaultLang; //'fr' or 'en' 
    
    if (currentLang == 'en'){
        return str;
    } else {
        //look up translation in map
        return map[str][currentLang]; //My App tête
    }
}