Hi Daniel,
UltimateWB is online software, so internet is required. The software is installed directly onto your web hosting, and you can create & manage your website from your own website admin panel then, from any computer with an internet connection. You can purchase web hosting from UltimateWB at https://www.ultimatewb.com/domain-names-web-hosting or from another company that satisfies the server requirements, as described at https://www.ultimatewb.com/server-requirements .
UltimateWB Lite/ Full do have full width image slideshows and galleries possible. We have created a sample for you to check out, which can be created with UltimateWB Full or Lite: https://www.ultimatewb.com/sample-slideshow . Also, we have a video tutorial on creating slideshows and galleries, and making them full screen width, on our Video Tutorials page at https://www.ultimatewb.com/video-tutorials . Here is the direct link to that YouTube video: https://www.youtube.com/watch?v=6H9kqWF1kq4 .
You can play around with the online demos at https://www.ultimatewb.com/demolinks . You can also check out the comparison chart to help you decide which version you would want to use for your website: https://www.ultimatewb.com/compare-uwb . In summary, UltimateWB Full and Lite have the photo slideshow/gallery app, and UltimateWB Full also has the e-commerce apps, as well as other apps.