№ 3. Optimizers
Clean Master, and other optimizers like that take care of clearing your cache and deleting unnecessary programs. However, most modern phones have this function in their system already which makes these apps useless. They also make the battery life shorter. You won’t make the system faster, you will only slow it down and get ads as a “bonus.”
№ 4. Built-in browsers
Built-in browsers are often installed on the phone system “out of the box” and they are mostly slow and not very popular. In most cases, built-in browsers are opened when you click a link. Unlike, for example, Google Chrome, these programs don’t have any protection from data interception and they slow down the system performance.