At Lensicle there is a range of tools you can use, here is a short overview of each.
Exact dimensions – when on any photo listing you can type in the dimensions you need the image to be and download it at that size.
Lightbox – as you navigate the website save your favorite photos in the lightbox.
Compression tool – downloaded a full size image? Reduce the size with this tool.
Lensicle image editor – edit any image, not just the ones listed on Lensicle, using the completely free tool.