1. A software development assistant method, comprising: acquiring, by an end user device, related test cases and execution tool thereof from a software developer device side for testing a function of a software at the end user device, wherein the related test cases and execution tool thereof are used to test the software on the end user device; executing the related test cases by the end user device using the execution tool with respect to the software; collecting execution information of the related test cases for feeding back to the software developer device side, the execution information including function usage information comprising a frequency that a specific function is used and a frequency that a specific error occurs for the specific function; determining at least one of a defect existing and a function frequently used in the software based on the execution information of the related test cases; and, deploying new software developed for at least one of the defect existing and the function frequently used in the software that are closely related to a function involved in the new software.