Lag has been one of Android‘s worst enemies. People don’t like lag. With hardware getting better and better and things like Project Butter, lag should be more and more reduced. This is very good, but old devices don’t benefit from this since they don’t have JellyBean, and/or the hardware is not as good as it is now. However, you can reduce lag on all (rooted) devices.
XDA member lambgx02 has created an app that will speed up your device and reduce lag without overclocking your device. The app will seed the entropy from /dev/random with the random data from /dev/urandom. The entropy pool is used to create randomness. This randomness is used for things like SSL to make purchases, log into your google account, etc. So when /dev/random runs out of random data, it needs to create more, and apps have to wait for that causing slowness and lag. The thing is, /dev/urandom uses a PRNG (Pseudo-Random-Number-Generator) to create good random data, while /dev/random uses your enviroment (e.g. sounds the microphone picks up, changes in signal strength from WiFi or cell towers, time between packets, time you leave your finger on the touchscreen, etc.) to create really good random data. So when seeding /dev/urandom to /dev/random you send the lower quality (it is lower than the /dev/random random data, but that doesn’t mean that it’s bad quality) to the other one for use, and that way it won’t run out of random data and your device will be fast. Feeding the entropy pool has the biggest effect on apps that use ssl, e.g. Google Chrome.
There are 2 apps available to do this. The first one is lambgx02’s ‘Seeder’. This one seeds /dev/urandom into /dev/random every second, preventing the device from sleeping. This may have a negative effect on your battery, but the app does not have a wakelock which would really affect your battery.
The second one is ‘RandomSymlinker’ by Schoentoon. This one symlinks /dev/urandom into /dev/random. Symlink is short for symbolic link, which is like a shortcut. By symlinking /dev/urandom into /dev/random, it becomes a part of /dev/random. This means that it doesn’t seed every second, and thus has no effect on your battery. This method is a little bit less secure than the other one, but again, that doesn’t mean it’s insecure, the other one is just a little bit more secure.