I have just released a read only version of my LS1 flash tool here:

https://pcmhacking.net/forums/viewtopic.php?f=3&t=3111

Write is in development, details are in that thread. More features will be added over time. You do not need to be a member of pcmhacking.net to read and download. I will subscribe to this thread here and monitor it for feedback also. Let me know what you think!