improve network error handling/messaging

app/util/toast.ts

@@ -0,0 +1,7 @@
+import { ToastAndroid } from 'react-native'
+
+function toast(message: string) {
+  ToastAndroid.showWithGravityAndOffset(message, ToastAndroid.SHORT, ToastAndroid.BOTTOM, 0, 180)
+}
+
+export default toast