Yeah it usually keeps you logged in for quite a while unless you clear cookies or use private mode. I’ve been using it on both iPhone and Android for months now. One time I was at a boring family gathering, sneaked to the balcony and played some roulette rounds — the wheel animation is really smooth on mobile, feels almost like a real table. If you ever want to see what games are optimized best for phones right now, this page lists them nicely:
https://spin-bara.net/ . Never had any lag issues even during peak hours.