This is a simple application that records various log types, and compresses them as a zip file. The logs are saved in the application's private cache directory named by the date and time.
You can access the zip files through the system document picker - Select the SysLog app to view collected log zips.
To enable access to some logs (Logcat and Radio) to SysLog, you will need to grant the READ_LOGS permision using a computer with ADB. ADB is part of the Android platform-tools, and you need to enable ADB access on you device.
From a command line with adb available, you can grant the READ_LOGS permission via the following command:
adb shell pm grant com.tortel.syslog android.permission.READ_LOGS
This command tells the phone's package manager to grant the READ_LOGS permission to SysLog.
There is a detailed guide from XDA-Developers for information on what ADB is, and how to set it up.
There is also some official documentation here.
Yes. When you access a device over ADB, you have some privileged access. This can not be done on the device.
Even with granting the READ_LOGS permission to the app via adb, it may still not be possible to get all logs without root access. The only logs that should work after granting permisssions are logcat and radio logs - the rest may still be restricted.