A screen-touch tester can be a very small tool: touch the display and leave a mark at that position. The pattern makes it easier to see which areas respond while moving across the screen.
The interaction
The original Android utility supported two Back-button actions:
- Press once to clear the marks.
- Press twice to exit.
Its store package was com.nhancv.screentouchtest. The earlier listing recorded an October 2017 update; this note preserves the interaction rather than claiming the application is still available or compatible with a current device.
This is a record of a touch-visualization experiment, not a hardware diagnostic certification. A responding screen does not establish the condition of every sensor or display component.