It would be sooo easy!

Just attach the N900 to the thing that is to be measured and throw it up in the air. Before that you do it once alone so N900 knows how strong you are and how high you can throw it. Then with thing attached N900 can calculate the additional weight by decrease of height. That's it.

Probably you'll need a new N900 for every measurement, but that's OK. Lifestyle isn't for free!