Thank you for your question! Participants are encouraged to submit entry materials in English or include an English translation or subtitles so that all of the judges can fully understand your submission. However, you will not be disqualified if you do not include an English translation in your video.
Please note that, per the Official Rules, "Applications must have English language support. (You are free to add versions in other languages.)" So you must include English support in your actual Gear App.