The Octobo app runs on iOS 6.0 and up, Android 6.0 Marshmallow and up, and Amazon Fire OS 5.6.4.0 and up. Any 7-8 inch tablet, like the iPad mini or Amazon Fire (7th Generation), are compatible with your Octobo.
Below are direct links to access the latest Octobo app on your compatible device.
iOS App Store:
https://apps.apple.com/us/app/octobo-abc/id1286484287
Google Play:
https://play.google.com/store/apps/details?id=com.ThinkerTinker.OCTOBO&hl=en_US
Amazon Fire: