I have written a small but utimately dirty hack to add an image to allow a image on screen to mimic a spacebar press. It appears on all devices, but was written for use on a tablet.

in Home.phtml, at the bottom under the :
<div id="fullscreen-entry"></div>
add
<div style="position:fixed;bottom: 0%;right: 0%;z-index:10;"><img src="../public/images/arrow-down.png" onClick="javascript:selfoss.shortcuts.spacebar();return false;"></div>

The position section of Bottom Right defines where I want it to appear, but Top Right also works.

Note that this is a quick and dirty hack, and does not fit in to the general design of the code.

Cian