I am looking to create functionality similar to this site: https://smartmockups.com/. - Source: Reddit / about 2 months ago
If you don't have Photoshop, there is this https://smartmockups.com/ really great website, it is also free, and you can just select a mock-up and add your png/design online, and they provide you with your pre-made mock up instantly. - Source: Reddit / 21 days ago
Freepik - More than a million free vectors, PSD, photos and free icons. Exclusive freebies and all graphic resources that you need for your projects
Placeit - Generate realistic product shots in seconds
Shutterstock - Shutterstock is a provider of stock photos, illustrations, and vector art. The website allows individuals to purchase a subscription and download copyrighted art for creative projects. Read more about Shutterstock.
Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.
Pexels - Find the best free stock images about Browser Home Page. Download all photos and use them even for commercial projects.
Magic Mockups - Place your product screenshot in real-life environment.Free iMac and iPad mockups ... read more.