Code reusing from crowd-sourced sites, specifically Stack Overflow (SO), is a widely practiced fundamental phenomenon in software development. However, severe consequences might arise if the incorporated SO code snippets contain code smells that cause software inconsistency. In particular, software bugs and failures cost trillions of dollars every year, including severe fatalities. This study reveals the impact of SO code fragments reused in mobile application codebase regarding software bugs and imminent maintenance. Additionally, we perform an intense analysis on reused code snippets (SO) and other (nonSO) code snippets for ten open-source and industrial projects. Later, we also investigate the regular properties of SO answers (i.e., answer scores and answerer reputation) to know whether those properties help identify appropriate SO fragments when reused, considering that 2.1 million SO code snippets are written in Java. The analysis exhibits, 1) the proportion of reused SO code is comparatively higher in industrial mobile apps than in open-source; 2) SO code fragments are significantly more change-prone than non-SO code; 3) SO code snippets are responsible for bug occurrence in later revisions, which is comparatively higher in industrial projects than in open-source ones. Besides, the SO code snippets cannot be judged whether it is buggy or not using the regular properties (i.e., answer scores and answerer reputation). Our experimental results can assist the SO, research, and mobile developer communities in strengthening re-usability concerns to facilitate code-quality improvement and minimize software bugs due to SO code.