Uptodown is an online service that provides users with access to a vast library of software and applications for their devices. It offers both free and premium software and applications for desktops, mobile phones, and tablets. It also provides users with updates to their existing software and applications, as well as access to a large community of users who provide feedback, reviews, and ratings for a variety of software and applications. Uptodown also has a blog and forum, where users can exchange ideas and experiences with one another.
One is multiplatform, the other is not.