Fossify Calculator

★★★★☆

Basic calculator with one-variable memory, like the cheap 16-key models you might find at the dollar store. Plus square roots and unit conversions. No trigonometry, no scientific notation, nothing fancy. But also no ads, no data mining, and no need to pay for a subscription. Probably not suitable for writing a lab report, but convenient for when you just need to split a bill or calculate a tip.