Android: Rather than waste time cranking out test shots, DOF Calculator takes your camera, lens and aperture settings and shows you the depth of field range for the photo.
For your average snapshots you might not consider or even care about the depth of field. When you're taking portraits, product shots, and other photos where attention to detail and a specific outcome are desired, having the right depth of field can make or break the photo. Plug in your camera model, focal length, aperture setting, subject distance, and the measuring system, and the DOF Calculator gives you the near and far focus limit, depth of field, and the hyperfocal distance.
Search for the "DOF Calculator" in the Android Market or scan the QR code here to download it. DOF Calculator is free and works wherever Android does.