Default SMS apps and N5/Android

I love my N5 and will never go back to the land of Apple, there I said that and feel better.

Now, with that said, I do have 1 bug that has been bothering me for awhile. The one app that I miss from my years with iPhones is the bitesms app. It was nothing fancy really, just; notified you when a message comes in, lights up the screen, shows the message and allows you to respond. I've been using ledblinker (don't have THAT iPhone now do you) and 8sms + stock message. Now this works pretty good, but its not always stable.

So, what is the technical reason that this is such an issue? I tried most of the other sms apps in the store and nothing worked well for me. It surprises me that no one has created an app that mimics bitesms for android. Does android not allow this type of notification to be controlled programmatically?

I've tried handcent, chomp and go sms. I'm willing to try any suggestions, but I'm really curious as to why this is an issue.
Current
Nexus 5 - ATT; Rooted, Custom Recovery, Stock ROM

HTC One - ATT; Rooted, s-off
ROM: SinLess ROM GE