Create an online invocing application with expanse tracking. This application should have a contact book of  business partners (suppliers/customers). Information in the contact book must be validated in ARES. 
Application should provide interactive form to create an invoice to the customer. Invoice should be exported as a PDF, printable, sent to mail or available as an ISDOC. Look of the invoice can be chosen from template and possibly customizes by the user. All invoices can be displayed in sortable and filterable table. 
Similar form and table should be available also for expenses. With expenses user should be also able to upload image or PDF of the invoice. For uploaded images there should be option to use OCR to extract key information - like invoice number, date, VAT ID, total amount, individual line items. Include validation routines and allow manual corrections.