UI Jar might be a bit more popular than Sketchize. We know about 1 link to it since March 2021 and only 1 link to Sketchize. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
I used to get custom ones made at trulymine.ink, which were great and they are super customizable. I think this from your image is dotssy(?) which is not too bad either, but the same as the other one it's kinda pricey for what in the end is a notebook for doodling and throwing around ideas. Nowadays I just used a nice leuchtturm notebook with some sketchize.com templates stapled/taped in that I don't feel too bad... Source: about 3 years ago
UI Jar: This is one of the better ones for “general” category. Check it out yourself. It has some extensive filters. Source: 11 months ago
uiprint - Printable templates of mockup, wireframes and sketchpads
UI Movement - The best UI design inspiration, daily
Mockuper - Instant Mockup Generator
Design Hunt - Curated design inspiration for everyone
Mediamodifier - Create beautiful designs and product mockups in seconds.
Muzli - UI/UX and Design Inspiration Chrome Extension