I'm working on my third commercial tool for Unity, ClipSync. It's a track-based event timeline editor allowing to synchronize timed clips (Animation, audio, etc.) with any sort of game event.
This tool was born out of frustration with how animation events are currently handled in Unity. It replaces the limited, hard-coupled, string-based event triggered at a specific frame with a timeline editor allowing events to have a duration and time-based parameters.
The main inspiration for this tool is the fantastic Meowmaritus' DSAnimStudio, a TAE file editor used by many FromSoftware games. It's my most ambitious tool, and the main challenge lies in keeping the tool flexible and easy to use.