I have been frustrated by the difficulty of tracking how many drinks I've had. All too often, I'll wake up, hung over, and have to struggle to tally what I drank the night before. The fact that alcohol comes in different sized doses and at different concentrations, the best you can do sometimes is guess. And if you forget to write down your drinking for the weekend, and try to piece it together on Monday? Good luck.
I installed an app called Alcodroid. You set up presets for the drinks you typically consume. When you start a drink, you press a button and it logs the start time. When you finish, you press another button. The app tracks how many standard drinks you've had and even gives you an estimate of your current BAC, what your BAC will peak at, and what time it will be when it drops to zero.
This thing is a godsend. Last night, I had one 6.8% bottle of beer, followed by one 8.5% beer. I then went to the bar and had four pints of various strengths. Trying to compute the total from that accurately is damn near impossible, but when I woke up this morning, I had a very accurate log of exactly what I had drank the night before and what number to put into my drinking log. It gave me an 11. I probably would have estimated 9 if I had tried to work it out in my head.