Maybe I said it wrong, it is not like checking the source code, but if you concern about security and safety (like me), the minimun you can do it to understand what technology the app is using, what protocols, what type of data does it store, etc. You can check APT logs and see what dependencies were installed etc. If I installed an flashlight app and all of the sudden i see that apt installed a stmp server and a logger, it is a fishy app for sure.