IndigoCONNECT+ is the the companion app for the IndigoDUO unit, allowing for Bi-Directional text messaging, forms and various additional functions.
The app is available on both iOS (Apple devices), and Android
iOS (Apple) Download Link:
https://apps.apple.com/za/app/indigoconnect/id6445910075
Android Download Link:
https://play.google.com/store/apps/details?id=za.co.indigosat.IndigoCONNECT_&hl=en
Either can be searched on the various stores as "IndigoCONNECT" directly from the store.