I don't want to be negative on your launch day, but at the same time feedback is important.
1. I couldn't see myself or the many agile/lean teams I've been part of using this. I don't feel enough of a burden when walking the board for this to be worth the money.
2. A user in spinach.io costs effectively the same amount as a user in Slack, the difference is that I'm going to use Slack all day every day and assuming the use of this tool it's a once a day task.[0]
3. Bringing 'intention' and 'structure' feels a little like it will become a straitjacket.
4. Moving talking during a standup to 'prep time' seems like it would remove any of the time benefits you're quoting. Worse that time would better be spent updating Jira/Trello/whatever, people don't do this reliably, so the prep becomes one more thing that doesn't get done.
This is only one data point, and there is of course the classic "what do we need Dropbox for we have FTP" HN comment, so don't be disheartened either. As PG has said (paraphrased), one of the reasons to launch quickly is that you haven't really begun until you've launched.
Having said that I'm happy to continue providing feedback as you iterate (my contact details are in my profile).
[0]: Enterprise price point is incredibly hard. Got to get enough dollars to make it worthwhile, but that excludes smaller businesses like mine that feel like a death by a thousand cuts from all the SaaS subscriptions (I know you have a free plan).