I have T-mobile $30 pre-paid plan with 100 minutes, 5GB LTE data, unlimited text. I have Galaxy Note 4 with Wi-Fi calling which works pretty well. If I make/receive calls via Galaxy Note 4, does it count towards the 100 minutes?
VOIP (Hangouts dialer currently) has been my life saver on this plan. But the only number I give out is my Google voice number. That way I can pick up calls in an VoIP app or on my PC if I'm home.