FlashTimer is a free Android app developed by udele that helps League of Legends players track their opponents' summoner spells. The app is designed to be simple and easy to use, allowing players to quickly set up countdowns for each spell.

To use the app, players simply tap on the summoner spell that their opponents have just used, and the app will begin the countdown timer for that spell. If players need to change or cancel the countdown, they can hold down the spell they want to adjust. The app also includes a feature that allows players to set up custom timers for other important events, such as jungle respawn times.

Overall, FlashTimer is a useful tool for League of Legends players who want to keep track of their opponents' summoner spells and other important events during the game. The app is free to download and easy to use, making it a great addition to any player's toolkit.