I think I have the same sentiment as other developers here. I just opened my gistbox today when suddenly a notification pointing me to cacher appeared.
The UI and overall experience looks great. But having no github gist was such a downer for me as well. Reason for this is I might present my source code to the public or paste it in medium one of these days. And gistbox is a great way for me to manage all my gist snippets.
Though best of luck to your startup.