diff --git a/lib/appium.js b/lib/appium.js
index f0c8e3940..ce5ac9668 100644
--- a/lib/appium.js
+++ b/lib/appium.js
@@ -531,6 +531,7 @@ Appium.prototype.initDevice = function() {
       , robotPort: this.args.robotPort
       , robotAddress: this.args.robotAddress
       , isSafariLauncherApp: this.isSafariLauncherApp
+      , desiredCapabilities: this.desiredCapabilities
     };
     this.device = ios(iosOpts);
   } else if (this.isAndroid()) {
@@ -554,6 +555,7 @@ Appium.prototype.initDevice = function() {
       , keyAlias: this.args.keyAlias
       , keyPassword: this.args.keyPassword
       , systemPort: this.args.devicePort
+      , desiredCapabilities: this.desiredCapabilities
     };
     if (this.isChrome()) {
       androidOpts.chromium = this.args.chromium;
diff --git a/lib/devices/android/adb.js b/lib/devices/android/adb.js
index 9c475faac..fc49c533f 100644
--- a/lib/devices/android/adb.js
+++ b/lib/devices/android/adb.js
@@ -658,6 +658,9 @@ ADB.prototype.startApp = function(pkg, activity, waitActivity, cb) {
     if(err) return cb(err);
     if (stdout.indexOf("Error: Activity class") !== -1 &&
         stdout.indexOf("does not exist") !== -1) {
+      if (!activity) {
+        return cb(new Error("Parameter 'app-activity' is required for launching application"));
+      }
       if (activity[0] !== ".") {
         logger.info("We tried to start an activity that doesn't exist, " +
                     "retrying with . prepended to activity");
diff --git a/lib/devices/android/android.js b/lib/devices/android/android.js
index 3ad724f56..0691d6172 100644
--- a/lib/devices/android/android.js
+++ b/lib/devices/android/android.js
@@ -60,6 +60,7 @@ Android.prototype.initialize = function(opts) {
     , javascriptEnabled: true
     , databaseEnabled: false
   };
+  _.extend(this.capabilities, opts.desiredCapabilities);
 };
 
 Android.prototype.start = function(cb, onDie) {
@@ -190,6 +191,9 @@ Android.prototype.pushStrings = function(cb) {
   } else {
     var stringsFromApkJarPath = path.resolve(helperJarPath,
         'strings_from_apk.jar');
+    if (!this.appPackage) {
+      return cb(new Error("Parameter 'app-package' is required for launching application"));
+    }
     var outputPath = path.resolve(getTempPath(), this.appPackage);
     var makeStrings = ['java -jar "', stringsFromApkJarPath,
                        '" "', this.apkPath, '" "', outputPath, '"'].join('');
diff --git a/lib/devices/ios/ios-log.js b/lib/devices/ios/ios-log.js
index c61744a6e..c79fe6854 100644
--- a/lib/devices/ios/ios-log.js
+++ b/lib/devices/ios/ios-log.js
@@ -35,18 +35,18 @@ IosLog.prototype.startCapture = function(cb) {
   if (this.udid) {
     var spawnEnv = _.clone(process.env);
     spawnEnv.PATH = process.env.PATH + ":" + process.cwd() + "/build/libimobiledevice-macosx/";
-    spawnEnv.DYLD_LIBRARY_PATH = process.cwd() + "/build/libimobiledevice-macosx/:" + process.env.DYLD_LIBRARY_PATH
+    spawnEnv.DYLD_LIBRARY_PATH = process.cwd() + "/build/libimobiledevice-macosx/:" + process.env.DYLD_LIBRARY_PATH;
     this.debug("Starting iOS device log capture via idevicesyslog");
     this.proc = spawn("idevicesyslog", ["-u", this.udid], {env: spawnEnv});
   }
   else {
     if (parseInt(this.xcodeVersion.split(".")[0], 10) >= 5) {
       this.debug("Starting iOS 7.* simulator log capture");
-      this.proc = spawn("tail", ["-f", "-n0", process.env.HOME + "/Library/Logs/iOS Simulator/7.0/system.log"]);
+      this.proc = spawn("tail", ["-f", "-n1", process.env.HOME + "/Library/Logs/iOS Simulator/7.0/system.log"]);
     }
     else {
       this.debug("Starting iOS 6.* simulator log capture");
-      this.proc = spawn("tail", ["-f", "-n0", "/var/log/system.log"]);
+      this.proc = spawn("tail", ["-f", "-n1", "/var/log/system.log"]);
     }
   }
   this.proc.stdout.setEncoding('utf8');
diff --git a/lib/devices/ios/ios.js b/lib/devices/ios/ios.js
index 6fd6bfe82..26f7bb202 100644
--- a/lib/devices/ios/ios.js
+++ b/lib/devices/ios/ios.js
@@ -76,6 +76,7 @@ var IOS = function(args) {
       , databaseEnabled: false
       , takesScreenshot: true
   };
+  _.extend(this.capabilities, args.desiredCapabilities);
   this.supportedStrategies = ["name", "tag name", "xpath", "id"];
   this.localizableStrings = {};
 };