Requirements:
Apple iPhone or iPad, Generation 3 or greater (Bluetooth 4.0 or greater)
UPDATE 2/1/19: Thanks to one of our great customers they discovered that if you "clear Bluetooth cache in hidden apps" on your Android Mobile device, the Guitar Tunes app for Android and the Fretlight work.
For reference, here is the fix in Android 8.1 (Oreo) -
Go to System Settings > Apps and Notifications > select "See All" > in the top right corner select "Show System" > Bluetooth > Storage > Clear Cache
Instructions for an LG Stylo 4 with Android 8.1.0, and Bluetooth 4.2
- Download Guitar Tunes from the app store.
- If your "location" is not set to "on" in your Android's settings you must do so. This is important.
- Next, make sure your Bluetooth is "on".
- At this point do not connect/pair your Fretlight to your Android's Bluetooth manually by going into the Android's Bluetooth settings as you usually would do to pair a device. If you have already paired your Fretlight just unpaired it in the Bluetooth settings and clear your Fretlight by holding down the Fretlight button till all the lights on the neck light up.
- Next open Guitar Tunes and when you work your way to a page that has the fretboard displayed. There also should be a Bluetooth icon on that page.
- Press the Bluetooth icon. It may ask for permission to access your location, select "ok".
- Next, quickly press the button once on the Fretlight and Guitar Tunes should see the Fretlight. Click on "name your guitar" and name it. - - The Fretlight guitar should be paired and ready to light up.