Here are free downloadable Hanon piano exercises from The Virtuoso Pianist - Part 2 by Charles L. Hanon. Part 2 exercises should be tried after you feel very comfortable with all the exercises in Part 1. If you haven't done so, please see all the exercises in Part 1. Part 2 exercises help farther developing strength and independence of each finger as well as preparation for trills and crossing the thumb under other fingers and incorporating wider intervals (extensions). It is important for you to follow the fingering numbers that he suggested for you to benefit from the exercises and improve your skills. Some of the exercises in Part 2 are written in the only one-octave pattern. However, you may try two octaves. You may also refer to the recording to make sure if you are doing the exercises correctly.
To learn more about the creator of The Virtuoso Pianist, Hanon, please visit our page, "About Charles Hanon."
If the Part 2 is too challenging for you, please try Part 1. They are also free.