The Twinkle uses a responsive web interface, controlled from a modern web browser on any device. The interface is hosted on the device itself. You connect to it when your device is on the same WiFi network as your Twinkle.
My Keen Glow
If your device has cloud enabled (the default), it will be available on the My Keen Glow website. You can also access this site with the Manage link in the upper right of this website. This is the best way to find your Twinkle if you’re not familiar with your local WiFi. When you first set up your Twinkle, it provided you with a unique ID. This is a long string of random characters and numbers. Use your ID on the My Keen Glow website to connect to your Twinkle.
The Fing App
If for some reason you can’t use the first method above, the Fing app may be helpful in locating your Twinkle. It’s available for both iOS and Android. Once installed, run a scan on your LAN and look for any devices of type Expressif. Then open a web browser to the given IP address.
Your router is likely the device that assigns addresses to devices on your WiFi. It’s likely you can see the list of assigned addresses and devices on your router’s interface. Every router is different, but you’ll want to look for DHCP. Once you find it, open a web browser to the given IP address.
If all else fails, you may need to reset the device and reinstall it.