Authentic contextual learning (ACL) with mobile apps near home became prevalent and promising due to the COVID-19 pandemic since students were asked to learn near home without going to school. However, learning with mobile apps may cause problematic issues, such as anxiety and acceptance of either students or parents. This study aims to investigate students' learning achievements and anxiety and acceptance of students and parents toward ACL with a mobile app, called UG, in two different places, Taoyuan-Taiwan (TG) and Yogyakarta-Indonesia (YG), during the COVID-19 pandemic. The results indicate that students' achievements in both places were significantly improved. Regarding anxiety, significant differences were found between students' and parents' anxiety in both places; a high positive acceptance of students and parents in both places implies no significant difference. In addition, we discuss the different correlations of students' mobile phone entertainment daily usage, parents' educational levels, anxiety, acceptance, and achievements between TG and YG.