Have a way to calibrate resistive touchscreens.
Many ARM mobile devices made for GNU/Linux have resistive touchscreen.
This is more precise, but requires calibration.
Some GUI exist for that such as xinput-calibrator, which work with evdev.
Alternatively there is also tslib, but xf86-input-tslib isn't in officially maintained by Xorg. This is problematic because there is no guarantee that at a given time, xf86-input-tslib still matches the current Xorg API.
We also have the option of calibrating manually with xinput, but that is really tedious and not user friendly. Though it sometimes gives better results.
We could also somehow have a package that ships calibration data, but that might be complicated to integrate seamlessly, especially if users are supposed to mess around with the system. It also cannot support every device that ever existed.