This is not a standalone application. NeuStyle Pack widgets require the KWGT PRO app (not the free version of this app).
What do you need:
✔ KWGT PRO app
✔ Custom launcher like Nova Launcher
How to install:
✔ Download the NeuStyle KWGT pack app and KWGT PRO
✔ Long press on the home screen and select the Widget
✔ Choose KWGT Widget
✔ Tap the widget and choose NeuStyle KWGT pack installed.
✔ Choose the widget you like.