Let go of the stick and it flies itself
Flying on a phone just got quieter. The mobile autopilot has no button and no gesture to learn — the stick itself is the switch. Take your thumb off it and the plane flies itself; put your thumb back and you have the controls again.
The stick is the switch
So the toggle went away. A thumb on the stick means you are flying the plane; lifting it means you are not. That is the entire interface. Let go of the stick and, after a short beat with your thumb off it, the autopilot latches — the centre ✈ AUTOPILOT flag lights and the plane holds its heading, straight and level. Touch the stick again and it drops on the same frame; you have the controls back instantly, mid-manoeuvre, no gesture to perform.
It fits how the plane already behaved. Releasing the virtual stick eases the aim back toward level on its own — but only loosely, and a trimmed-out warbird left alone will slowly roll off and wander. The latch is what turns that soft drift into an actual hold: once your thumb has been gone a moment, it captures the heading you were on and keeps it there against gusts and trim, so a stray thumb-lift to work the throttle or swing the camera leaves you flying arrow-straight instead of sagging into a bank.
The two things it won't do
It won't grab the plane the instant you spawn: a fresh cockpit gives you that first beat of manual control before the latch is even armed, so you leave the runway flying it yourself. And it won't hijack a stunt. If you're inverted over the top of a loop or pointed near-vertical when your thumb comes off — the one time auto-levelling would openly fight you — the latch holds its fire and lets you finish the move. Every other attitude, it catches and levels, because a hands-off plane that's rolling off is exactly the plane that wanted catching.
The best mobile control is the one you never learn. No button, no gesture, no tutorial line — just take your thumb off the stick, the way you'd take your hands off a real yoke, and let the aeroplane fly.