Is there shortcut to switch between visible windows (apps) within current desktop? I have 3+ windows (different apps) placed on a single desktop. Also i have bunch of other desktops with other windows-setups.

How do i toggle focus between visible windows of current desktop?
If you go to Settings -> Keyboard -> Shortcuts in this area you can set the following keyboard shortcuts to achieve the toggle focus between windows on your current desktop. Please see this screenshot for further instructions. I use macOS 10.12.2 (Sierra) on a late 2015 Macbook Pro 15.