FTAdjust is a brand new jailbroken cydiatweak has been released in Cydia which allows you to adjust folder title size
you want. If you want to customize your text size then FTAdjust can help you.
Tweak Name : FTAdjust
Author: Cole Cabral
Repo: BigBoss
Price: Free
Description:  For those who didn’t know FTAdjust is a
cydia tweak which allows you to change the folder title size
accordingly.  
FTAdjust is a brand new jailbroken cydiatweak has been released in Cydia which allows you to adjust folder title size you want.
Like you can make your
folder text smaller or bigger in size you want. You can configure more in the
tweak preferences from the settings app after installing this tweak. You don’t
need to respring your device.
Compatible: This tweak works on all
iPhone, iPad and iPod touch running iOS 9 or later.
If you are not yet jailbroken then
follow this step by step guide on How to jailbreak iOS 9 – 9.1 using Pangu?