You can not control it, using your phone screen alone, without the controller.  You might be thinking, big deal, why does that matter....

Think about it this way, if you want to travel light, and bring your mini along, having to bring the conroller too, is like bringing a second Mini, both in terms of size and weight.  Not cool for a drone that's all about portability.
DJI: please make an in-app controller available in the next DJI FLY update.

Cheap drones can do that. But they connect via phones wifi and have range of 100m tops. So controler is there for distance and for controlling drone.  I had yuneec breeze drone that is controlled with smartphone and i couldn't get past 60m. It sucks. And mini is already most lightweight and smallest drone ever made (for it's specs and capabilities)

Luka_BiH_ Posted at 6-27 20:49
Cheap drones can do that. But they connect via phones wifi and have range of 100m tops. So controler is there for distance and for controlling drone.  I had yuneec breeze drone that is controlled with smartphone and i couldn't get past 60m. It sucks. And mini is already most lightweight and smallest drone ever made (for it's specs and capabilities)

I wouldn't expect the mini to go nearly as far without the controller, but even 300 - 500 ft range from a phone controller, would make it useful in many situations.  

trader6777 Posted at 6-27 20:59
I wouldn't expect the mini to go nearly as far without the controller, but even 300 - 500 ft range from a phone controller, would make it useful in many situations.

The Mini is too limited for many purposes already.
But your suggestion would make it even more handicapped.

The Mini also lacks the ability to be replaced with only $30 when it crashes...

Buy Tello

They use to have this feature on older Mavic's like the original Pro and Air 1 but it was very unreliable and many crashes occurred because of it - probably why they scrapped it on all of their new releases in the past couple of years. I tried it once and never again. You will have much better control with the RC and I strongly doubt you'll ever see this feature on the Mini.  

The Spark does it, but I can’t say I’ve ever used it without the RC.

You can do it with spark Mavic pro but nobody uses it, you’re also confined to 100ft and height 50ft that’s if you can get that range.

Remote control is approx 5x2” I’m sure 99.999999999% of people traveling will manage to fit it in so why would they bother.
I do also believe almost no one ever used this with Mavic pro.

Why would you want to be able to control it with a phone? Ok, as a backup maybe but I MUCH prefer a controller for its precision, e.g. compare the gimbal control. Then there is the question of control range.

Besides which, a screen is hard to see in bright day light etc.

Sean-newbie Posted at 6-28 07:53
Why would you want to be able to control it with a phone? Ok, as a backup maybe but I MUCH prefer a controller for its precision, e.g. compare the gimbal control. Then there is the question of control range.

Besides which, a screen is hard to see in bright day light etc.

When I had a MA it was very useful for b roll footage while mountain biking (even with the distance limit), very convenient to temporarily clip your phone to the handlebar.  

Excellent answer, I see your point, thank you,
Mind you taking a hand off the handlebars and concentrating on controlling a drone is perhaps not conducive to your safety and or the safety of others, as in car drivers using a mobile phone whilst driving.
Food for thought perhaps?

Hello there trader6777.  Thank you for reaching out and for sharing you insights with regards to this matter. I will cascade this thread to the designated DJI department for further attention. All significant suggestions or requests will be implemented after the evaluation of the DJI Engineers. For the latest updates on DJI please stay tuned to our DJI official website at www.dji.com. Thank you for your support.