I tried Lightflow back when I got my Galaxy Nexus (when it first came out). I could never get it to work correctly. Unfortunately, I tried it again now, years later, for my new Nexus 5, and I still can't get it to work correctly. I love how the developer is responsive and so willing to help everyone and make improvements all the time, but they never work for me for some reason. For my Galaxy Nexus, I ended up just switching my text app to Glowfly, which took care of the customized LEDs and notifications perfectly (note: It is a texting app, not a notification app; it just happens to work that way, though. Check it out if you don't like Hangouts or your current texting app!). Even though I enjoy Hangouts for SMS, I think I might switch back to Glowfly now for the customized LED notifications.