It is not a standalone application. Glass Pack widgets require the KWGT PRO app (not the free version of this app).
Supported Android
{5.0 and UP}
Supported Android Version:-
Lollipop (5.0–5.0.2) – Marshmallow (6.0 – 6.0.1) – Nougat (7.0 – 7.1.1) – Oreo (8.0-8.1) – Pie (9.0)

Download Glass for KWGT 1.0 Paid APK For Android

Gl__KWGT_v1.0_P.apk