Don’t worry, Eclipse 3 is a jailbreak tweak that enables system-wide night mode for iOS 9 devices.
Are you bored with white
color interface on your system? Don’t worry, Eclipse 3 is a jailbreak tweak that enables system-wide night mode for iOS 9 devices. You can now personalize your
devices you want with Eclipse 3. This tweaks also features blacklist functionality.
After installing this tweak, you have option to customize in the settings app.

You can enable or disable nightmode to which app you want,
You have themes & color option for keyboard, loading screen, status bar,
sms bubbles, dock, control center and much more.
Checkout some screenshots:
Eclipse
3
tweak is available in Cydia via the BigBoss Repo for $0.99 and is compatible
with iOS 9. This tweak is also available for iOS 8 as Eclipse 2(iOS 8) & Eclipse(iOS
7)
for iOS 7. 
If your device has
not yet jailbroken, then follow this step by step guide to How to
jailbreak iOS 9.0.2 untethered by Pangu
.