If you have a new device or just have to reinstall the App for H!P Tap Live, it's possible to access your old account.
Once you have installed the App, get to the starting screen:
(The members shown on screen might change from time to time, but the basic design should stay the same.)
If you click the blue button on the top left, it will ask for your account's ID and password. To recieve these, you'll have to be logged into your account - this is why you should check it before deleting the App etc.! It would be best to write down the information or screenshot it.
In the main menu, click on the button on the low right in the menu circle, the one that looks like a grid that says "other". This opens the options menu. Here, you'll have to tap the button on the top right.
This should be the next screen that you see. For now, we're only interested in the 3rd option, so tap that.
After tapping it, your ID and password appear on the screen. As said, you should write it down.
After getting your data, you can now enter it on the starting screen. Voilá, you transferred your account!