Not sure if Hiya is powered by T-Mobile but I've heard of that app powered by Hiya.
I've found this Hiya - Caller ID & Block - Android Apps on Google Play . This link is directly for androids. Not sure if they also have it for iOS users but you should be able to type on your app store Hiya Call Blocking and it should appear.
On the Hiya Site There is a reference to several different carriers including T-Mobile
They even have a picture (graphic) of the "T-Mobile Name ID" App
T-Mobile Name ID - Android Apps on Google Play is the app I believe you're looking for. Just found it today myself - I'm not sure why they have two different apps, or if one is a different service, but I love this one so much better than the one they pre-load on Android phones!