Based on our record, Google Design Sprint Kit seems to be more popular. It has been mentiond 1 time since March 2021. 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.
Also Google (as in the company not the verb) has a free version of their discovery techniques here https://designsprintkit.withgoogle.com/. Source: about 1 year ago
Design Sprint Kits - A pre-assembled kit for GV design sprints.
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
Design Principles - An open source repository of design principles and methods
Control Illustrations - 108 free flat illustrations with customizable characters
Land Book - The homeland for fine websites
Humaaans - Mix-&-match illustrations of humans with a design library.