Do you use calculator often? Android N might be useful for you
Android N Developer Preview 2 comes with small but useful features.
This one allows you to add calculator toggle to the notification panel, so that you do not need to open the app drawer and find the calculator. However, this is available for Google’s stock calculator, and we will probably not able to add normal apps to the notification panel because Google says,
“Quick Settings tiles are reserved for controls or actions that are either urgently required or frequently used, and should not be used as shortcuts to launching an app.”
It looks like not all rules apply to the Google. However, it would be really nice if you could add your favorite apps to the notification panel.