I use BattStat on my OG Galaxy S. Should be available for ICS. I like it because it's quite simple displaying your current battery level with an 'Eighty Percent', 'Fifty Percent', etc.
For those looking for a widget similar to the HTC one, search for "Battery Widget" by Elvison. It looks and functions Almost identical to the HTC one but allows you to adjust the settings.
I use Battery Life by curvefish, used it about a week or so on my OG Evo and now its on my LTEvo, very accurate, does what it needs, also has a setting to display temp and volts
Use "Battery Widget" by Elvison. Very accurate. Option to show percentage in corner of notification bar and when you click on it, it has a shortcut to Battery Use and settings.