I thought the preset uploading was going to be the hard part, but actually downloading the presets presented some challenges that I was unprepared for! Safari and Chrome on iOS simply would not download preset files, instead displaying them like text files. This is a somewhat understandable security precaution, Apple don't want you downloading random nonsense on iOS, but it's a bit overzealous and annoying for our purposes!
If you haven't been following the discussion of this problem in the comments section, there were a couple of workarounds. The easiest (for me) was for people to simply use different browsers. Puffin lets you "Download to Dropbox" where you can then "Open In..." the files with their appropriate app. iCab Mobile doesn't give a fuck and will let you download anything you want. Both of these solutions require the use of paid apps though, and I didn't want to force everyone to do that. Also, if you like your browser I don't want you to have to switch just to use discchord.
These are mobile presets, so you should be able to easily download them on your mobile device! One workaround on my end would be to either require, or force, all uploads to be .zipped. You could then open the zipped file in AudioShare, and then import presets from there. This was a pretty good idea, because I'm sure 90% of you already have AudioShare, and the other 10% of you probably should. But... I still didn't like the idea of forcing you to pay for an app to use the presets here.
This is where I'm really glad I spent most of 2016 writing discchord v3 from the ground up. Not only can I add site-specific features like preset sharing, I can write entirely new code libraries to make them work. So I did!
Now whenever someone uploads a preset to the site, my code will immediately mirror it to Dropbox. So the file exists both here on the discchord server cluster as well as inside of Dropbox's cloud. When you press the Download Preset button, one of two things happens. If you're coming to the site on anything other than an iOS device you will download the file as normal. This will also happen if you spoof your OS user-agent, so if you're an iCab Mobile Power User and just want raw downloads you can do that. But if you are on your iOS device; instead of downloading the file you will be redirected to a Shared Download Link on Dropbox.
Now the only app you need to have installed on your iOS device is Dropbox! And Dropbox is free!
You'll notice I've also tweaked the way iTunes links are displayed. Now you can see an app's Discchord Reader Rating, Comments on the AppDB, as well as a number showing how many presets have been uploaded for it. Dropbox is kind of a poor example of that, so here are the ones with presets available now. Clicking on the preset number, or icon, will take you directly to the presets page for that app.