Review the mistake. Try it again.
See how Kalkulko keeps completed games on your device, shows recorded answers alongside correct solutions, and offers a separate round to practise saved mistakes without a timer.
Download MP4 · English captions · Read the transcript
About these examples: this guide uses earlier English iOS screenshots from July 2026 and Czech iOS simulator examples from 8 September 2026. It is a narrated sequence of authentic still images. The active mistake-practice screen is not shown.
Ordinary rounds are timed. Saved-mistake practice is untimed. The app keeps the last 50 completed games on the device. The examples illustrate app controls, not measured learning results.
Produced by Yellow Bench on 1 October 2026, with an AI-generated English voice. Kalkulko is free and ad-free. Android requires version 8 or later; iPhone and iPad require iOS or iPadOS 18 or later.