Requirements

• First a server running Blynk to forward messages from the app to the Arduino microcontroller.
• Smartphone, I'll be using an Android phone. Use the Blynk HTTP RESTful API.
• An Arduino compatible board, I'll use the Huzzah again, with the Blynk library.

What about the app?

Will start with React Native, which requires Android Studio and JavaScript knowledge. This also means the code can be shared and run in Xcode for an iOS build.

Ideas

• Controlling a device attached to the board
• Monitoring a sensor attached to the board
• Logging activity on the smartphone and displaying on the board

Generally something along those lines, if you have any ideas please let me know!