Increase performance of android devices

Are you using an old android phone with less amount of RAM? You can increase the performance of the phone by this method. To proceed with this method, first you have to enable the "Developer Options" in android device. Here is the link for "How to enable Developer Options".
Once you have enabled developer option,

• Go to Settings -> Developer Options

• Under Developer Option, Select Window animation scale and turn off the animation.

This will improve the performance of an android device to some extent.