The Presto Insta-Shopper app is available for Android (version 4.1 and above) and iPhone/iPad devices (iOS version 9 and above).
To get the Android app: https://play.google.com/store/apps/details?id=com.surfmerchants.presto.insta&hl=en
To get the iOS app: https://itunes.apple.com/us/app/presto-instashopper/id1077411824?mt=8
I don't have an Android or iOS smartphone -- can I still do Insta-Shops?