matchbox-keyboard-im binary package in Ubuntu Xenial arm64

 Matchbox-keyboard is an on-screen 'virtual' or 'software' keyboard, designed
 for touch-screen devices running X.
 .
 Matchbox is a base environment for the X Window System running on non-desktop
 embedded platforms such as handhelds, set-top boxes, kiosks and anything else
 for which screen space, input mechanisms or system resources are limited.
 .
 This package provides a GTK+ input module for use with Matchbox-keyboard or
 other on-screen keyboards.

Source package