Where can I download this application on iPhone? I had a Samsung, and on Android I had this app.

It's on iOS too, so don't worry. Here's a look here https://aviator-ua.net/en/download/, just download it, and you can easily install it. I can also say from experience that playing on a phone or tablet is much more convenient than doing it in front of a computer monitor, especially if you're at work and everyone can see that you're distracted from the tasks set by the management.