What are some alternatives?
When comparing Fastnative and appenguin, you can also consider the following products
AppPresser - Build iOS/Android apps using WordPress with AppPresser.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
GoNative.io - Convert your existing web application into native Android and iOS
Website 2 APK Builder - Convert your HTML, CSS, JS and all other web content into an Android App within seconds.
MIT App Inventor - MIT App Inventor | Explore MIT App Inventor
AppInduce - The Next Generation DIY App Builder