Upgrading your SM-T116 with a custom ROM is the single best way to breathe new life into the hardware. It allows you to bypass official software limitations and extend the usable life of your device. The Problem with Stock KitKat on the SM-T116
Stock firmware files (also called "stock ROMs" or "factory images") are available from various sources online. The latest stock version for SM-T116 appears to be Android 4.4.4 with build numbers like T116XXU0APF3 and T116XXS0AQC2.
The stock Android 4.4.2 KitKat (or 4.2.2 Jelly Bean, depending on your region) is not only ancient but painfully slow. Apps crash, the UI lags, and most modern apps from the Play Store no longer support those old OS versions.