Teams launching SaaS products overseas often face troubles in localization testing: they want to check if the interface seen by German users fits German typography but can’t replicate the local device display; over 10 regional test accounts crowded on one computer may cause test data confusion due to IP association; they receive feedback from Southeast Asian users that "button positions are awkward" but can’t simulate the operation experience of local mobile models in real time. Yajuzhen Cloud Phone offers simple solutions to these problems. Its localized device simulation function can accurately replicate usage scenarios in different regions — when testing the interface for U.S. users, it calls up Los Angeles IP + English system + iPhone 15 adaptation mode, allowing you to see the layout of the "Submit" button in an English context; when optimizing interactions for Japanese users, it switches to Tokyo node + Japanese system + local Android models, with even font sizes and button spacing matching what local users see. A project management SaaS tested and found that the text overflow issues in the German interface identified via the cloud phone were 60% more than those found through traditional testing. The efficiency of multi-region parallel testing has improved significantly: three test accounts for the U.S., UK, and Australia can run simultaneously to verify the spelling adaptation of "color" and "colour" and regional differences in payment processes; test data is automatically classified by region, with click heatmaps from U.S. users and operation paths from European users remaining separate. What used to require batch testing can now be done simultaneously. A CRM software team calculated that after using the cloud phone, the localization testing cycle was reduced from 15 days to 5 days. Real-time feedback handling is more timely: upon receiving feedback from Singaporean users that "the login button is not noticeable", you can switch to the local device mode in the cloud phone with one click and locate the problem in 3 minutes; for complaints from Berlin users about "form submission lag", you can reproduce and record the lag nodes after simulating the German network environment. A collaboration tool SaaS used this method to reduce the resolution time of user feedback from 48 hours to 6 hours, increasing the user retention rate of the localized version by 30%.