The Spiral Tattoo by Michael J Parry, published by Sky Warrior Books, is 0.99 at Kobo right now. No idea how long it lasts, since I think it is primarily due to Kobo lagging when it comes to raising the price again. ( It is 2.99 at Smashwords.)
The Blurb: Law comes in two sizes: six inches and eight feet. Elanore, the eight-foot tall troll, and Gurt, the six-inch tall (don't you dare call me a fairy) Eleinu, both guardsmen in the city of Delvenport, tackle their most baffling case yet. When they find a dead waitress, naked except for an intricate tattoo in a spiral across her body, they're launched into an adventure ...