I wanted an SPL Meter on my iPhone as a back up and to check levels at gigs etc. so bought the really expensive £0.69 Studio Six Digital SPL Meter app.
This quick test isn’t the most scientific of experiments but I’m really happy how close the app performs next door to the RadioShack model using the same settings.
The meters are just over one metre away from the studio monitors.
Here’s the link on iTunes if you fancy checking it out: