I'm on iOS, so I have no idea how I would go about adding a timer to my video.

If splits.io worked, I would've provided splits alongside the video. Maybe I can use a video editor and add Livesplit alongside the video?

Have you discord ? If yes join it : https://discord.gg/jxNzKew And our "IOS helper" will help you

Yeah, I joined the discord. I'll ask there.