Based on your search query, I would recommend ScratchJr as it is specifically designed to introduce young learners to the world of programming. It uses a block-based coding system with icons instead of words, making it easy for children to understand and use. This feature can be particularly useful in teaching algorithms, as it allows students to visually construct and manipulate sequences of instructions.

Moreover, ScratchJr encourages cognitive development, helping students develop logical thinking and problem-solving skills, which are crucial when learning about algorithms. The platform also allows students to create and share their own interactive stories and games, promoting collaborative learning experiences. This could be a fun and engaging way for students to apply their understanding of algorithms.

Lastly, ScratchJr serves as a stepping stone for more advanced programming languages like Scratch, Java, and Python. This means that as students progress in their understanding of algorithms and coding, they can transition to more complex languages, making ScratchJr a sustainable tool for long-term learning.