How to save a number while being on a call in an Android phone?

This is a situation everyone is familiar with, i.e., searching for a pen and paper during a call to jot down important stuffs, like phone numbers or addresses. Our instinct is to search for writing materials to write down something during a call as we ignore the importance of this feature on the phone that we are using. If you use the dialer to write down a number, the number will disappear after the call ends. (more…)