Standalone Software

We are a small practice and currently only use Excel.  I am looking to pay an annual fee for standalone software that can be used to input information from invoices receipts etc.  I do not want anything that is paid for per client. I have used Transaction + in the past if anyone is familiar with that and am looking for something similar.  For information most of our clients bring their paperwork in a Tesco or Asda carrier bag.  Thank you.