Is there any way to access the console logs on an iOS 8 device without installing Xcode?

Yes. Apple Configurator 2 has a command line tool that can tail and/or dump the console logs and do some other nice operations like pair, enumerate connected devices, etc...

cfgutil syslog

That's the official Apple way and it's much smaller a download than Xcode. Both are free but cfgutil is much more powerful and can do things like remove apps, erase, pair, and even run scripts when you attach and detach iOS devices to your Mac.

To make cfgutil available at the command line, open Configurator 2, and choose Configurator 2 -> Install Automation Tools ... from the menu.

You could also look at homebrew and install libimobiledevice - that is open source and free as well and seems to be kept updated fairly well over time.

brew install libimobiledevice

There is a tool called iTools

It provides real time system logs just like Console log in iPCU or xcode

• Connect Your device to system.

• click on itools->Under iPhone->>Advanced->System logs

With iTools 3.1.9.8 (available for Mac & Windows) you can get logs from your iOS device by selecting Toolbox and Real-time Log: