Share button on all app with Secret Project effect

[Rufy86]

Hi,
I've a tab bar-based app and I would like to show the button on all app. How can I do it? Furthermore, I would like to add the button behind the tab bar, so when the button expands after the click, the effect is like shown in Secret Project:https://dribbble.com/shots/1928064-Secret-Project. How can I do it?

Thank you

[zsy78191]

You should add this button at [UIApplication sharedApplication].keyWindow.