LoLAbsent 20.10.11 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The actual developer of the free software is tecnobillo. The program is included in Games.
From the developer:
LoLAbsent allows blocking the League of Legends contact list. So you will be invisible when you want to play alone. You can play with a friend if you enter the same game room before blocking the friends list. Let no one bother you!
Simply select your region (EUW, NA, LAN, LAS, etc) and click the "Lock" button to lock the friends list, or click "Unlock" to unlock it.
You may want to check out more software, such as LoL Absent, which might be related to LoLAbsent.