my favourite apps are Activator and Springtomize
Activator allows me to have any physical action do almost anything on the phone, for instance, holding the volume up button skips the song, and volume down is set to pause/play. my thumbs unlock my 5S (typical fingerprint scanner abillity) but the ring finger on my right hand locks it and so does swiping along the bottom of the screen. right index finger launches Chrome, triple pressing the home button brings up the Music app etc etc
Springtomize is purely cosmetic. custom lock screen, custom phone lock animation (it looks like when you turn an old tv off), page swipe animation, 5 icons in the dock instead of 4. nothing mind blowing but those two and a few others are all I really needed to make it perfect for me