My phone started dying on me when the battery was around 20%. This means that, in most cases, I didn't even get to see the low battery warning.
When my phone was able to show it, I knew that the battery was only going to last a couple minutes. So, the original warning was completely useless.
I tried re-calibrating the battery, clearing the cache, and installing a new ROM. None of this worked.
That's when I decided to develop this workaround.
I hope you guys like it and find it useful :)
If you have any feature you would like to see on this app, just let me know by email.