i really liked these two by noah boyd
the bricklayer
agent x
i just supplied both kindle versions here, i personally have a kobo and have them for that device which i got on kobo books.
i'm sure there are other places to get them though.
they both moved really fast and i liked the styling of it and the puzzles they hero had to go through and the writing is light and fun....i'm a huge fan of books like that, ones i can get into and 3 days later be satisfied...like your regular blow em up movies !!
edit: the bricklayer is book 1 and agent x is the follow up. i do hope he writes more.