For anyone interested, I've been using 'ring it up', it has estimating, invoicing goods inventory, stock control a very capable package for the money IMHO Avis St OC packages.
cost £22, so while at the more expensive end of iOS apps, a real cheap book keeping or POS program for anyone running a small business, be a great starter for anyone interested in account programs and perhaps becoming a book keeper.
Most small businesses that fail within 2 years, do so not because of incompetence but mostly due to lousy paperwork and poor book keeping