Both NODE Sensor Platform for iOS (NODE-IOS, discontinued) and NODE Sensor Platform for iOS and Android (NODE-IA, discontinued) support:
iPad 3 or newer
iPad Mini
iPhone 4s (iOS 6 or newer)
iPhone 5, 5C, 5s

Additionally, NODE Sensor Platform for iOS and Android (NODE-IA, discontinued) supports:
Samsung Galaxy S2, S3, S4, Note, and Tab
HTC One
Google (LG) Nexus 4 or newer

Other Android devices may work, but have not been tested.

For the most up-to-date information, visit:
https://support.variableinc.com/hc/en-us/articles/202020268-What-smart-devices-are-compatible-with-NODE-