We want to re-build an application for Child Care. We built and deployed previously - https://thebackseat.net/. But due to in accuracy we withdraw from the app store. I want to go with flutter or react-native. I searched out many options but I did not get any success on either side. I have couple of questions if any one from the great community can help solving this. Speed detection. App will monitor the speed of car every after some time interval. The distance between two co-ordnates devide time is the logic but not happening on iOS. Any idea? App is required to be in background constantly even if it is not activated by mobile user. So Foreground, background are both mandatory. How can this be achieved.  The purpose of this app to save life of toddler. Suggestions are most welcome.  Thanks in advance.