Are these apps still available to any devices, cause i can't get them from store on my 520.
These apps are still available and is supported in Windows 10 mobile. But they are supported only for certain mobile models it seems. Unfortunatly Lumia 520 is not on the list. Here are some details :
Lumia Camera Beta:
Lumia Camera Beta is available for Lumia 930, Lumia Icon, Lumia 1520, Lumia 640 and Lumia 640 XL
Supported phones : Lumia 930, Lumia Icon, Lumia 1520, Lumia 640 and Lumia 640 XL
Supported OS : Windows 10 Mobile & Windows Phone 8.1
Lumia Camera CLassic :
Supported phones : Lumia 830, 930, 1520 or Icon.
Supported OS : Windows 10 Mobile, Windows Phone 8.1 & Windows Phone 8
Lumia Camera used to be available only to phones with PureView cameras - this might still be the ca case for 8.1.
In Windows 10 the Lumia camera is basically the default camera - but that won't help your 520 unfortunately.