Yes this is only a browser, but works fine – Koala Browser - Sleep Better Review

This is a decent browser that does exactly what it says it does. The ads are annoying (and aren't color corrected), but you can get rid of them for 99¢. A lot less glitchy than unblue, a competing app that costs $2.99. I wish the color change affected the keyboard also.
Review by Matthewser on Koala Browser - Sleep Better.