CalcTape Paper Tape Calculator
There are plenty of basic and fancy calculators available for iPhone, many of them going for free. CalcTape takes it to the next level though. It combines a desktop calculator and note app on your phone to allow you to perform daily calculations more conveniently.
CalcTape lets you perform complex operations and review everything. If you have missed a step, you can easily add it later. The app lets you create templates, functions and text snippets to save time. Your calculations are synced across all your devices.
CalcTape is ideal for accounting, expense tracking, tax calculations, and other similar operations. You can get it for under $3 at this time.