Have used a spreadsheet for years. Moved to Billyapp last year - which has been fairly good and helps to see a big picture. Now moving to the HR and accounting system that my bank provides for "free", as part of a business account. Mostly because that makes me tax compliant. Biggest mistake I have ever made was not having a system for taxes in place when I started being self-employed, and now making a transition to products. So hoping I get all of this correct, before I launch and try to make sales.