Offer a complete solution for online accounting software
VERY wild idea, but seeing as you've got a very good platform, it might be worth looking into diversifying and actually offering a service for users to manage their accounting. If people can simply upload and backup their bills and invoices with you, immediately allocate them into the branch where it belongs, input to who the money goes, and manage the rest of their entire budgets and finances right with you, and making sure you can use all this data from a certain time-period and have it synchronously go into a budget-map, you can offer a very solid base for a SaaS product. Desktop apps, Slack integrations, mobile apps, a complete solution to make sure you're right on top of your finances. I for one would definitely use this!