Depth of Field Android App?

[bmattock]

I decided to install a "Depth of Field" calculator app on my Android phone. I see that there are dozens if not hundreds of them out there. All seem to be rated fairly highly. I realize I could just carry a cheat sheet as I did in the 'old days', but since I always have my phone with me (company phone, I'm required to carry it at all times), I thought it would be a nice little app to have.

For those who are using an Android app for DoF, which do you prefer? What makes it better for you?

I'm frankly looking for 'free', but I don't mind paying for something if it really does a good job.

Thanks!