Cache cleared, checked permissions, phone resarted and app uninstalled and re-downloaded... Its strange all the other widgets work fine. It looks as though it registers me tapping on the apps, but they just don't open. I've emailed app dev to look into it.
Did you also attempt to update Google Play System? If not then do it via Settings>Security and Privacy>Updates. There are usually two updates available so you will need to repeat the process after the 1st update.