Background story: I applied to 10+ companies a month ago. I did keep track, I did follow up etc. Couple of them didn't follow up, couple of them I remembered not replying last time I applied for them as well. Nothing changed. I was tired of Excel, Notepad, Gmail.
The pain you're describing is being handled by at least 10 companies that I know and which sent me updates about the jobs. Granted they're not the best, but they work.
The pain I wanted to reduce was the pain that comes with the entire process. When you're simultaneously in 10+ process it can become easy to lose your focus and forget to follow up, read notes, to dos (google most recent interviews etc).
The pain I also wanted to remove was the pain of re-applying to companies that are god awful at providing feedback, that do not reply, that forget to close job ads etc. Think job app history.
Another pain I wanted to remove was weighing the offers via charts and summaries on the offer page and show communication and interest from the company on the reports page.
Another idea as suggested in comments:
Provide this data transparently, blind the important information and that might take the product to a whole new level.
I do not want this to be another job board or an email newsletter. There are plenty out there.