free kp-Books

Offline accounting for small businesses. Sales, Expenses, Invoices, Inventory.
Sales, Expenses, Invoices, Inventory, journal entries.
It gives you the ability to work offline without the need of an internet connection.
There is also another (non free) version of this app with exra capabilities like the following:

• Manage many businesses
• Sync data between many devices or computers
  More details at www.kapapi.com