If you don’t know a resistor from a Mister Mister, this is the app for you. Built by Adafruit, creators of DIY Arduino gear, Circuit Playground is a $2.99 app designed to help you identify and understand various electronic components. For example, the app includes a resistor identification system based on the colored bands painted on the casing as well as a field guide to many electrical components.
The rest of the tools – including converters, calculators, and datasheet storage systems – just makes things a little bit easier when you’re building an electronics project. I’m terrible at this stuff so it would be a boon for me and my slow-witted monkey mind.