Have you ever tried to guess the number of M&Ms in a jar? Not as easy as it looks. This app, however, should make your next guess much more accurate. This will allow you to mathematically estimate how many M&Ms are in any sized container.

If you know the volume of the container, it's a only a two step process. Just enter the volume, select the unit of measure, and tap 'calculate results'.

If you don't know the volume of the container, simply use the ruler provided to make an estimate (Only works with cylinders).

The better your volume estimation, the closer the results will be. In testing, results were within 20 for a large jug and closer for smaller containers.

NOTE: Only works with regular M&Ms. Peanut M&Ms will not work. No other candy is supported at this time, but may be included in a future update. All measurements are in US Liquid.

See this blog post for math and original idea:
http://lifehacker.com/5324692/guess-the-number-of-mms-in-a-jar

My math is slightly modified and produced closer results in testing.