OfflineSurveys supports multilingual surveys (since 2017/version 1.32)
While LimeSurvey fully supports multilingual surveys and switching between different languages, there are some technical limitations for running such surveys offline e.g. switching the language at survey runtime means loading the new language texts from the server which is not possible when running a survey offline.
For running a survey with multiple languages you have to add each survey language variation as a stand-alone survey at the OfflineSurveys app. For example survey …/limesurvey/index.php/867775 comes with languages AR, EN and DE and thus needs to be added 3 times:
When later syncing the data of the different language versions with the main Limesurvey system, all the response details will be added to the same survey at Limesurvey (the one with survey ID 867775). So even if you run different language versions of a survey at OfflineSurveys, the data will later be merged at Limesurvey automatically.