Site Collector is an application that can take snapshots of websites. These snapshots are taken in the form of high resolution images. These will include the entirety of the website. This means that the application will scroll down to capture everything on the website. It should be noted that this is not a website downloader. In other words, Site Collector will not let you browse the target website and then browse it offline. It will simply take a picture of it for future reference.
To get the application started all you need to do is click on the "+" sign in the bottom left corner of the screen and type the URL of the site. You can additionally set a capture scheduling time. This basically allows the application to automatically take snapshots of your desired website at regular intervals. This is great because you can simply configure the app and leave it running in the background. The available time options range from 10 minutes to 24 hours.
In my testing, I added a random website and let Site Collector do its thing. I simply sat back and saw it regularly take snapshots of the website. The resulting images looked great. I like the option, that allows you to see the snapshot in Preview or Quick Look.