The thread is old, but: ‘Assoluto Racing’ seems to be closer to sims than something like ‘Real Racing’, and also has fewer annoyances begging for payments (I couldn't stand RR3 at all). There are multiplayer races, at least there were some time ago when I played—however cars don't collide, they go through each other; and I can't remember if there were only one-on-one races or larger grids too. But the game does have decent physics.
Even though one can turn the phone to simulate a wheel, onscreen pedals are quite a nuisance, so I would just buy a gamepad with a phone holder instead.
Also, in lieu of phone apps, a better option in some respects might be to use an emulator and old console games. Certainly no in-game payments there. But idk if PS2 emulators are any good on a phone these days, or one is still limited to PS1 and DOS games. ‘Indycar Racing 2’ is probably an option.