This tweak might not seem very useful or worthwhile to a lot of folks, but having the iPhone's lock screen dim within seconds is annoying to some and incredibly annoying to others (me). This is probably due to the fact that when I am sitting at my computer I am usually either reading things or writing things, and I am always checking/using things on my phone as well, like the notification center and calculator, both of which can be accessed from the lock screen. The problem (and yes, it certainly falls into the category of first world problems) is that I will hit the home button on my phone so it lights up, but then I continue reading what's on my computer screen for a few more seconds, at which point I have to hit the home button again because the lock screen has dimmed. Thus begins the vicious cycle. But no longer - a new tweak called LockScreen Extender has solved the issue.
LockScreen Extender does exactly what it sounds like - it keeps the lock screen up for a period of time of your choosing. Once you have it installed, head to Settings -> LockScreen Extender. Inside, you can enable the tweak, then you can pick your "Dim
Delay." You can choose 20, 30, 40, 50 seconds, 1, 2, 3, 4, 5 minutes or an hour. You can also choose a different delay time for when your phone is plugged in. Just keep in mind your battery life when choosing the first delay time. Another option lets you hide the date and time on the lock screen. Although it says that you only need to respring if you choose to hide the clock, I had to respring for the delays to take effect as well (though this could have to do with the many other tweaks I have installed).
So if you feel you need your lock screen to stay lit for a little bit longer than the default time, you can download LockScreen Extender from Cydia's ModMyi repository for 99¢. It requires iOS 7 or better.