Photo Mate allows you to customize your editing interface.
Histogram
Go to Menu -> Histogram to choose the Histogram mode or to disable it
Top bar
Use the to unlock the bar from the top.
Editing tools
Long-Tap on an heading (like "Basics") to re-order the tools.
Note: You should close all tools first by tapping once on each of the headings
Sidebar size
Go to the "Tools" heading and use the "Sidebar Size" slider to adjust the width of the tools section