Launching a lightweight automated expense categorization

I am currently building a receipt scanner or expenses scanner to categorize expenses using AI technology. Imaging having your receipts in one place and categorization is automated, ready to be sent out to your accountant for tax purposes? This can be used by small businesses, personal or even students.

I'm curious: What's the biggest pain point you face when managing your expenses? Would you find a tool that simplifies tax preparation and categorizes items for your accountant helpful?  What are the most frustrating aspects of managing receipts?  What features would you like to have in a expense categorization tool?