Unlike many mods, Appleskin has no complex GUI configuration. However, you can tweak some values via a config file or mod menu (if you install a GUI mod like Mod Menu – not common in 1.8.9).
Manual config: Navigate to .minecraft/config/appleskin.cfg. You can edit:
Defaults are usually fine for 99% of players. appleskin 1.8.9
Appleskin is microscopically small. The mod JAR is under 50 KB. It adds:
On a 1.8.9 client, you will not see any FPS drop. In fact, on a low-end machine, Appleskin might even improve your awareness, stopping you from spamming food open inventory, reducing lag spikes. Unlike many mods, Appleskin has no complex GUI configuration
This is the million-dollar question for competitive players.
The short answer: Yes, absolutely.
AppleSkin is a client-side visual only mod. It does not send extra packets to the server. It does not automate eating (auto-eat is banned on most servers). It does not give X-Ray vision or movement hacks.
Note: While AppleSkin itself is safe, do not use "Auto-Eat" forks of AppleSkin. Those are considered unfair advantages because they automate player input. Defaults are usually fine for 99% of players