Mobile app login issues

I am a new customer, made the switch from AT&T a week ago, and brought my family with me. I activated 5 new lines and an Apple Watch, purchased 4 new phones. I have completely given up on logging into the mobile app..  It is 100% useless, and speaking with customer support about it leads precisely nowhere. Logging in on iPhone gives me a login boot-loop in the form of -alternating between a pretty, magenta-colored spinning wheel and "Processing"- endlessly. Nothing happens. Logging in on Android does something very similar. The only way I'm even able to check my accounts is by logging into the website, and at times, that is just as buggy and just as frustrating!

I find it hard to believe that a company of this size, one that is throwing obscene amounts of money at building a new, modern cellular network, can't afford to hire a competent app development team… The company points you in the direction of the mobile app everywhere, tells you about it every time you're on hold while on the phone with customer support. To not back that up with an actual WORKING app is a bit ridiculous.

The fact that I ( and from what I've read, many other customers) have the same exact problem on multiple mobile platforms tells me that it's some sort of account related glitch, probably something relating to account security/user login/identity verification issue. There appears to be no way to contact or leave a comment for the developer, and, as I stated above, speaking with regular customer support leads absolutely nowhere. Based upon the complaints I've read, many other T-Mobile customers are experiencing the same thing, and have been for a LONG time. For this to be an ongoing problem for so long is entirely unacceptable. Entirely unprofessional. Very frustrating…