Regardless of your playing level, or whether you are preparing for a piano exam, finger exercises are one of the keys to achieving technical fluency. These finger strengthening exercises give you the chops you need to tackle your pieces (AKA "repertoire").
This is a list of 15 of the most popular books of finger exercises for piano. If you click on the link, you'll go to a page to order it (or get more information on it):
Piano Essentials: Scales, Chords, Arpeggios, and Cadences for the Contemporary Pianist (Book & CD)
The First Book of Scales, Chords, Arpeggios & Cadences (Alfred's Basic Piano Library)
Master School of Virtuoso Piano Playing: Volume I Finger Exercises (Dover Music for Piano)
Oscar Peterson - Jazz Exercises, Minuets, Etudes & Pieces for PianoMaster School of Virtuoso Piano Playing: Volume I Finger Exercises (Dover Music for Piano)
Burgmuller, Czerny & Hanon: 32 Piano Studies for Technique and Musicality: 1
Twenty-Five Easy and Progressive Studies for the Piano, Op. 100: Piano Solo
Hanon: The Virtuoso Pianist (Complete) (Alfred Masterwork Edition)
Your eyes aren't deceiving you. There are several different editions of Hanon's exercises - all of them are pretty popular.