A new free jailbroken cydia tweak called “Torch on Focus” by Guy Kaplan lets you turn torch flash on and captures clear photos while
focusing your Camera in low light situations. Torch on Focus tweak brings improvement
on your photography in low light condition by using the LED flash while focusing camera. 
So if you
are jailbroken and have interest in photography then you must install the Torch
on Focus tweak which helps you to capture photos clearly in low light condition.

While focusing on Camera, “Torch on Focus” tweak actually turn on the LED flash to make your photo brighter and captures clear photos even in low light condition.
It is so difficult to capture photos from
iPhone’s/iPad’s Camera in low light condition as it has no clarity in picture
and have a broken pixel. While focusing on Camera, “Torch on Focus” tweak actually
turn on the LED flash to make your photo brighter and captures clear photos even in low light condition. 
Torch on Focus tweak is available in Cydia
BigBoss repo for free and is compatible with iOS 9 and iOS 10.

After installing this tweak you can have
option to configure from the tweak preferences in the Settings app where you
can enable or disable the tweak.
To make well-functioning, you need to
enable your Camera flash to On or Auto because Torch on Focus tweak won’t work
if your flash light is Off.

Tweak Name : Torch on Focus
Author:Guy Kaplan
Repo: BigBoss
Price: Free
Description: Turn on LED flash in Low light condition while focusing.
Compatible: Supports all iPhone, iPad running iOS 9 and 10
If you are on iOS 10 and has not yet jailbroken then follow this simple steps on;

How to Jailbreak iOS 10.1.1 Using Yalu app and Cydia Impactor [Windows]
How to Jailbreak iOS 10.2 using Yalu and Cydia Impactor

Try Torch on Focus and improve your
photography in low light condition.