This is the first app I have paid for and is very useful on a daily basis in the field.
iOS & Android Apps
The developer is an Ohio resident so the Ohio Cop App is probably even more useful. Rumor has it that there is an upgrade for this app that will up the price a bit, but I'm hearing evidence photo capabilities due to a time, date, and GPS stamp on the photos taken using the app. This way you can email your evidence custodian or DA scene photos with an email trail chain of custody. This app is well worth the $2 I paid.