_leo said:
Version 0.4b (and, I suspect, 0.3 and 0.4, as they also crash) throws the following error for me when I run the app:

E/AndroidRuntime(13531): java.lang.RuntimeException: Unable to instantiate application com.android.tools.fd.runtime.BootstrapApplication: java.lang.ClassNotFoundException: Didn't find class "com.android.tools.fd.runtime.BootstrapApplication" on path: DexPathList[[zip file "/data/app/de.e621.rebane.a621-2.apk"],nativeLibraryDirectories=[/data/app-lib/de.e621.rebane.a621-2, /vendor/lib, /system/lib]]
E/AndroidRuntime(13531): 	at android.app.LoadedApk.makeApplication(LoadedApk.java:507)
E/AndroidRuntime(13531): 	at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4301)
E/AndroidRuntime(13531): 	at de.robv.android.xposed.XposedBridge.invokeOriginalMethodNative(Native Method)
E/AndroidRuntime(13531): 	at de.robv.android.xposed.XposedBridge.handleHookedMethod(XposedBridge.java:631)
E/AndroidRuntime(13531): 	at android.app.ActivityThread.handleBindApplication(Native Method)
E/AndroidRuntime(13531): 	at android.app.ActivityThread.access$1500(ActivityThread.java:135)
E/AndroidRuntime(13531): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
E/AndroidRuntime(13531): 	at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime(13531): 	at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime(13531): 	at android.app.ActivityThread.main(ActivityThread.java:5001)
E/AndroidRuntime(13531): 	at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(13531): 	at java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime(13531): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
E/AndroidRuntime(13531): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
E/AndroidRuntime(13531): 	at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
E/AndroidRuntime(13531): 	at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(13531): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.android.tools.fd.runtime.BootstrapApplication" on path: DexPathList[[zip file "/data/app/de.e621.rebane.a621-2.apk"],nativeLibraryDirectories=[/data/app-lib/de.e621.rebane.a621-2, /vendor/lib, /system/lib]]
E/AndroidRuntime(13531): 	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
E/AndroidRuntime(13531): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
E/AndroidRuntime(13531): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
E/AndroidRuntime(13531): 	at android.app.Instrumentation.newApplication(Instrumentation.java:975)
E/AndroidRuntime(13531): 	at android.app.LoadedApk.makeApplication(LoadedApk.java:502)
E/AndroidRuntime(13531): 	... 15 more

Is anyone else experiencing these problems? I'm running Kitkat 4.4.4.

As for that, Xposed seems to be causing the problem. I tried running it on my old xposed phone as well and the same thing happened. Try uninstalling it from the Xposed launcher (cause its that easy on Kitkat) and it should work, as Xposed changes the runtime and the app isn't really prepared to run in situations like that