I tested Highster specifically on a Samsung Galaxy S23 running Android 13 because I wanted to see the modern Android experience 
Here is the short version. Install went fine. Calls and SMS populated within an hour. GPS location showed up correctly. Browser history came through. Everything else was a mess. WhatsApp showed zero messages despite being the most used app on the test device. Instagram same result. The keylogger did capture some text but missed chunks of input, especially in third party apps. Battery drain was also significant, the phone was losing charge noticeably faster with the app running. On a flagship phone running a recent Android build, Highster is simply not performing at the level it advertises. Older budget phones on Android 9 might tell a different story.