Simply have both the League of Legends Client (must be LCU) and this app open at the same time and the main screen will be populated with all your skins.
Q: Is there a way to make it work with the old client?
A: No. The old client is about to be discontinued, therefore this app was designed from the ground up with the League Client Update in mind.
Q: Will I get banned?
A: I doubt it.
Q: Can I use this on Mac OSX?
A: Not yet.
Q: This app looks a lot like the League Client Update, why?
A: I like how the LCU looks and wanted this app’s users to feel at home by using an already familiar UI.
Q: Can I contribute?
A: Sure, feel free to open issues and/or PRs.