Mockuptime is the ultimate collection of beautiful, realistic PSD mockups to showcase your work. Available for free, just how you like it.
Instant iPhone X Mockup is a open source tool for making iPhone X mockup fast. Just drag and drop the image to the iPhone frame and it will be wrapped into the phone screen. (No uploading and loading.)
Placeit will cut your efforts in finding the perfect mockup design for your products! You can find a variety of free mockups and demo videos suitable for your marketing. You can get a paid subscription for more options like discounts on watermarked designs, logos, and videos!