Digital Level Meter is described as 'Display sound level With 0.1dB resolution readout, Ideal for accurate steady state measurements, but also has PPM ballistics. See the ME/12 for more details of this'. There are seven alternatives to Digital Level Meter for Android, iPhone, Android Tablet, iPad and Mac. The best alternative is AudioTools. It's not free, so if you're looking for a free alternative, you could try Sound Meter or Sound Level Meter. Other great apps like Digital Level Meter are Audio Tool (Paid), Sonic Atom (Paid), Sound Meter by Splend Apps (Free) and Decibel X (Freemium).
You can measure the environmental noise in decibels. Sound Level Meter is the part 4. of Smart Tools series. (noise) Acoustimeter uses your phone mic to measure noise volumn in decibels(dB) and shows a reference. SPL(sound pressure level) noisemeter.
Decibel X is one of very few noise meter apps with highly reliable, pre-calibrated measurements and supports dB468, dBA, dBC. It turns your mobile device into a professional sound level meter, precisely measures the sound pressure level (SPL) all around you.