HP iPhone Calculators

Turn your high-tech iPhone into a decades old single-purpose device with HP iPhone Calculators. The range includes the legendary HP-12C Financial Calculator ($15) — the company's longest and best-selling model — and the HP-15C ($30), a high-end programmable scientific calculator capable of handling complex numbers and matrix calculations. Both apps replicate the classic looks and button layouts of these venerable old gadgets, adding plenty of old-school charm to your decidedly new-school device.