Air-o-Graph

This app is for those who have purchased an Apple HomePod and, like me, you want to use it to play your record collection. With no audio inputs on the HomePod, this can be tricky. I made this app for myself to aide in the process and I think others could probably benefit.

Before purchasing this app, please be aware of the entire setup you'll need in order to use it as I've described below. Also, please be aware that there is some audio delay (a few seconds) and so if you're using it as a microphone output it's is slightly weird.

Setup description:
Ultimately, you need to convert the audio output from your pre-amp or receiver to a mono microphone input (or line-in) to your iOS lightning adaptor. Generally, you'll need the following (though some products are available which can combine some of these steps.)

1) From your pre-amp, you will need to combine the left and right channels to a mono channel. Do NOT use a Y-cable, they do not properly combine the channels and you'll be very sad.
1a) If your preamp output is RCA, you can likely use:
Channel combiner: https://www.amazon.com/Galaxy-Audio-JIBR-RCA-Combiner
RCA to 3.5mm plug: https://www.sweetwater.com/store/detail/CMR206--hosa-cmr-206-6-foot-3.5mm-trs-to-dual-rca-cable
1b) If your preamp output is a 3.5mm stereo plug (standard headphone plug), you can use this:
Channel combiner: https://www.sweetwater.com/store/detail/MiniSumBox--switchcraft-318-mini-audiostix-1-channel-passive-laptop-direct-box
XLR to 3.5mm: https://www.sweetwater.com/store/detail/XVM101F--hosa-xlr-female-to-right-angle-1-8-inch-trs-cable-1-foot
1c) It's possible that if your receiver output has HDMI, you can go directly from that to lightning, but I haven't tested this and it might not recognize the audio as a line-in device. If you try it and it works, mention it in a comment!
2) What you now have is a mono signal, you need to convert this to a microphone input. There are a billion of these on the internet, here's one: https://www.amazon.com/ENVEL-Convertors-Smartphone-Microphone-Simultaneously/dp/B01M0T6PSF
3) You'll then need your iOS 3.5mm to lightning dongle. That's this: https://www.apple.com/shop/product/MMX62AM/A/lightning-to-35-mm-headphone-jack-adapter

Once you have everything connected, start up the app and press the airplay button. It should share your input as you'd expect.

I'm happy to take requests for improvements or features. There are a few that I'd like to have, if there's interest in the comments, I'll push the features here as well.

There will never be ads or information collection for this application (in the current version or any future version).