Ardu Companion is a companion t0 use in your daily projects and experiments with electronics prototyping.
The tools include: calculators for Timers, PWMs, ADCs (these three tools are for free and 100% functioning), other tools include: sample codes for timers, PWMs, ADCs, watchdog, debouncing and serial-data management, tools to obtain the values of resistors and inductors from the color codes on the components, the Ohm’s law, calculators for RC/RL/LC/RLC filters, voltage dividers, the series/parallel resistor circuits, the time for charging capacitors, the usage of op-amps, how to calculate the resistor for LEDs, how to configure an LM317 voltage regulator, how to use an NE555, and how to calculate the heat of a silicon junction (these tools are offered with in-app purchase of $1.99).
When using the calculators for timers, PWM, and ADC, if you tap on the “?” button you’ll get a brief explanation on how that peripheral works and what are the registers to configure it (tap on the floating info window to close it). Fill the required fields and tap on the Compute button to calculate the values you need. Tap on Clear all to clear all the fields.
I would have liked there to have been another couple of tools for free to entice you in personally, I will admit the price of $1.99 to upgrade is reasonable though and won't put a dent in the wallet. One thing I commend the developers for is not simply rehashing the Arduino online pages in an app, the amount of those I have looked at is not funny – admittedly mainly on Android devices.
I have a video of the app and I navigate through the freely available tools
Video
Here is the app on my iPad
App Store Link
https://itunes.apple.com/us/app/ardu-companion/id772038244?mt=8#
