I've been using textic toolbar (www.textic.com) which is similar. It
changes the colour of the background, text, font size etc.. It works
on the internet and word but you have to pay something to download it.

I've been surprised by how much putting an anti-glare screen cover
over the screen has helped me.

Other things that help generally are daylight bulbs, painting the
house in colours that suit me, anti glare window film and wearing
sporty sunglasses that have foam around the edges to stop light
creeping in.