ET use on the job a lot – Electronic Toolbox Pro Review

Update 6-2017: Still impressive after using several years. I'm a lifetime electronics technician and can testify this is what gets you going in the right direction for most of your formula needs. I appreciate that the developer continues to support the app for well over a year since I bought it. Bugs squashed before I knew it was a problem.
Review by Powerup777 on Electronic Toolbox Pro.