Termux Android 4 [better] -

In the rapid churn of mobile operating systems, Android 4.4 KitKat (released in 2013) is a relic. Yet, millions of devices—from point-of-sale terminals to e-readers and dusty tablets—still run this decade-old OS. For developers and hobbyists, the dream of repurposing these devices as lightweight Linux terminals has long rested on Termux, the most powerful terminal emulator and Linux environment for Android. However, the story of Termux on Android 4 is not one of seamless utility, but of graceful degradation, community forks, and ultimately, a poignant lesson in software obsolescence.

If you are trying to use Termux on an older device for academic or technical writing—specifically a "complete paper"—here is how you can manage that environment: Compatibility & Alternatives termux android 4