No longer maintained and soon will not be needed per this post, cheers 🍻

https://github.com/mvllow/clib/releases/tag/v0.4.1

Clib is a League of Legends login helper, using either a completely automatic or manual method.

Clib opens the League client and enters your password directly, avoiding the need to copy your password to the clipboard.

⚠️ Paste location is based on pixel values and may be innaccurate on some screens. Please use a unique password!

Clib will copy your locally-stored password to the clipboard, clearing after 25 seconds. Paste it via ctrl+v.

Neither Clib or mellow are associated with League of Legends or Riot Games. No information is collected by Clib. Any data entered into Clib is only saved on the user's local device. No information is gathered outside of this application, therefor Clib does not know your username.