If looking to move the app from an old iPhone to a new one here is a copy/paste from the Strelok iOS page:
To move Strelok Pro from old iPhone to new iPhone (with the same Apple ID!) use this application: https://imazing.com/ Here is useful video:
I helped a friend do it when he got a new iPhone, it worked perfectly.
In my case my phone did an auto update after google removed it from the App Store so all I had was the icon on my screen, no app as such. Fully recovered with imazing.