Yes, they are both from the same developer. TAUT is testnet coin and this app (
https://play.google.com/store/apps/details?id=com.mofei.tau) is for TAUT. If you dont have TAUT, you shouldnt even pay attention to this application. Though, you can buy testnet coins from the community in p2p groups (
https://taucointalk.org/index.php?board=144.0). It is now very cheap. On January 1st, 2020, these coins will swaped onto the main TAU coin in the ratio of 1 : 1.
I found out what it was.. TAUT is the second coin, developers felt sorry to close the test network TAU and they did it. Looks like greed.

*lol this another crap and why the dev needs to create even second coin and they can't even create the one properly? Just curious about why people are still interested to burn their phone by mine this crap coin.
if that was a second coin and does it build in the same blockchain? or it uses a new one as per the app is not even merged into the one app.
As I said before, mining of the TAU coin will not load your phone at all thanks to it's unique algorithm, you can see in the application how much power and memory it uses.