So I understand that MKJogo/MKLoL is bannable for it having the jungle timers and such, but is something such as Skin Preview ( http://mobaskins.com/skin-preview-league-skins-free/ ) allowed, as it only has the cosmetic client side skins? I read somewhere that it is allowed, but Riot doesn't encourage it because it might contain malware of sorts. If anybody can clear this up for me that would be great!
Riot doesn't endorse them.
categorized as "use at your own risk", some have gameplay mods to improve your decision making, some have malware / spyware in it.
It is technically modifying your client, which is technically against the terms and conditions. But Riot has said that they are not issuing punishments for this, but that could change if it becomes a problem.
There are plenty of ways to preview skins (without modifying your client) if you're considering purchasing them. Here are two tools that I use:
