I just created a free chrome extension for low time alerts.
It has:
- Custom low time notifications with a few different sounds
- Optional 5 second countdown
- Optional screen flash if you're hard of hearing
You can find it here: https://chromewebstore.google.com/detail/chesscom-low-time-alerts/ndfkkhkkmekhknheeoecnkogaodjecmd
Hopefully this is helpful for you 
I just created a free chrome extension for low time alerts.
It has:
- Custom low time notifications with a few different sounds
- Optional 5 second countdown
- Optional screen flash if you're hard of hearing
You can find it here: https://chromewebstore.google.com/detail/chesscom-low-time-alerts/ndfkkhkkmekhknheeoecnkogaodjecmd
Hopefully this is helpful for you
When i click the link it says it is currently unavaialable. Do you know why this might be? Thanks!!
This is such a no-brainer quality of life adjustment. Invariably, the purists are going to object that "over-the-board you don't get time warnings". Yeah, you don't get premoves either, or highlighted legal moves.
My wishlist (which I'd consider fairly achievable & maintainable from a web dev perspective):
Adjustable low-time threshold per time-control (at which the shaker-sound plays)
Option to replay shaker sound each new turn during low-time
Option to change clock colour during low-time
The current system is pretty barebones, and puts hearing-impaired players at a disadvantage.
Edit: Browser extensions are great, and I'm glad people are making them, but we need an actual solution in the site.
I play rapid 10/5 mostly these days and I think it would be preferable if I could adjust my low time warning to 5 or 10 seconds. 1 minute doesn't help especially when my time remaining hovers around 10 seconds when I've used up all my time and getting 5 seconds back each move.
If anyone knows how I can do this for rapid that would be great. If not, I think it would be handy for chess.com