There are a lot of cool League-related projects by independent developers. On this page, I'll give you a quick introduction to some of my favorites.
Disenchanter is a simple Windows tool also built by me that allows you to quickly mass handle most types of loot. Its main purpose is to help you quickly disenchant all of the champion shards you no longer need to Blue Essence. To make sure you don't lose any of the shards you might need later (to unlock the champion or Mastery 6/7), there's a variety of options to choose so you get just what you need.
You can download it on GitHub:
DarkIntaqt's Challenge Tracker is a versatile and comprehensive tool that offers players an efficient way to get in-depth insights on their challenge progress. You can quickly get an overview of the rank-up requirements for your challenges and their associated titles, view visualizations of your general progress and even game- or date-based breakdowns of your recent activity.
There's also a wide array of leaderboards for each challenge, even those not natively supported by Riot.
ARAM Zone is a site with stats focused on All Random All Mid. You can view your personal stats with game count, winrates, average KDA and multikills. There's also a champion tierlist that allows you to quickly access the most popular and highest winrate builds for each champion.
OneTricks.gg offers build and matchup information for each champion, derived from high elo one trick players. This allows players to get in-depth insights on what signature builds can be found among the best and what the general consensus on the best rune and itemization choices are.
I'm the developer of Disenchanter.
Otherwise, there's no affiliation or paid promotion between Mastery Chart and the projects. Any logos are used with explicit permission.