While you are typing in a whatever text editor app, whenever you want to create a data stamp:

1. Just tap the date stamp bubble. Then the system keyboard picker will pop up.

2. Select "H Bubble Date". Then a date and time stamp with the following format will be pasted at once.

-- 2014-05-21 06:03:14 PM




In case you are using the recent versions of Android, you can use the keyboard switcher button at the right bottom corner of the screen, as shown in the second last screenshot.




Features:

-- Different colors of bubbles are available for you to choose.

-- One of them is almost transparent.


-- If you use Google Keyboard, you can create a date and time stamp using only one tap.

-- Custom formats: You can set up any date and time formats you want.


-- Besides as a date stamp creator, you can also use this app as a Keyboard Switcher.

Whenever you tap the Bubble, the Android system's keyboard picker pops up.

In other words, you do NOT have to swipe down to go to the notification drawer.

This app saves you that step of swiping every time you switch the keyboard.