Backstory: Recently I had to find a new outsourced developer for a small project. My gut was telling me his progress was slowing but he assured me he would meet the deadlines. Upon a deeper check on his progress, he was extremely behind. I definitely dropped the ball managing this resource but having a rough heartbeat on his progress would help.
The Idea: A daily report on developer project progress.
Deep Dive: This would tap into the github or bitbucket and monitor the overall number and completeness of commits. Additionally it would monitor the complexity of commit messages. A quick tell for poor work quality is a high frequency of 1-3 word commit messages. Using this data you can get a sense of the pace of a developer.
This product is also useful when dealing with an outsourced team so you can monitor their daily progress without git access.
Validation: This would have noticed a trend and help alert me weeks before I finally made the call to find a new developer. This is a fairly object and can be an roughly accurate guide for progress.
Monetization: You could charge per repository. Using this model, your customer lifetime value would scale to provide additional revenue.