This will be helpful in beadwork. Beads are usually metric, whereas finished product is not. This will also be useful in crochet, as yarn is measured in both.
Now, how soon do you think it will be until weights will be added? And maybe add angle functions, degrees and trig functions for calculating round craftsmanship (and volume).
The fact important equations can be starred and labeled is added value. It works offline, too!
Jake Hasler, you have a fine product going here. Congratulations!