How to create start up scripts using the init.d folder?
In my version of Android (cm11 / LolliKat) there is a 90userinit script in init.d that tries to run a script named /data/local/userinit.sh if it finds it.

I've not tried this, but naming your script /data/local/userinit.sh might do the trick.

[I know it's an old question, but for posterity...]