This app was mentioned in 11 comments, with an average of 3.36 upvotes
Mixing Station. It's made by a third-party developer but it's good enough that Behringer links to his app on their download page.
Congrats! Everyone here keeps saying iPad but I've used both an iPad and an Android tablet (not even something new... an Asus Nexus 7, from 2013) and it's night and day, unofficial Android app for the win. The graphic design is a joke in comparison, but the usability is miles ahead.
Get Mixing Station for Android. Has a matrix patch like Yamaha.
I used to put my tablet in follow mode and place it on the display. Instant touch screen EQs and a variety of other things. Best $5 I ever spent.
https://play.google.com/store/apps/details?id=com.davidgiga1993.mixingstation
https://play.google.com/store/apps/details?id=com.davidgiga1993.mixingstationpro
A $100 android tab will do that job on a X32 much better than an iPad will and also save you a lot of money.
https://play.google.com/store/apps/details?id=com.davidgiga1993.mixingstation&hl=en
Well nuts. That explains it... I'd found myself drawn to the Mixing Station app as it seemed to offer more features that I was looking for early on. After years of using it, I didn't even consider there was another app. I'll look into it. Thanks everyone!
https://play.google.com/store/apps/details?id=com.davidgiga1993.mixingstation
or the Pro version - it is AWESOME... and when you start it you can limit what controls you can fiddle with. There is an iOS version too.
By the way - the P16 solution is very very good - works well for our church.
Oh, sorry, no, the iPhone doesn't have a full mixer app, AFAIK. You can only mix a single aux channel. I have a little Android phone that has the Mixing Station XM32 app. It's not worth getting an Android specifically for, but it's certainly nice to have at times like that.
Do you mean for remote control? There's a great android app that enables you to do that. I actually only have it installed on my android tablet and not on my iPhone. Here it is. I haven't had any problems with it, but admittedly I haven't used it much.
The app is now free as the developer is getting support from Music Group.
https://play.google.com/store/apps/details?id=com.davidgiga1993.mixingstation&hl=en_US
All depends on your budget. The absolute most bang for your buck would be getting an X32 Rack (even though it's way overkill for what you need) and using it with a wireless router because the 3rd party remote control app (Mixing Station) is absolutely amazing, and the X32 has amazing processing built in that goes WAY beyond just EQ. You can also then use it as your main mixer and control the levels of everything you're running through the system, including the system itself, wirelessly from anywhere within range of your wireless router.
If the X32 is too expensive, the next best thing that is cheaper is the QSC TouchMix 8. Using this again with a wireless router is also a fantastic route, and I use it on a regular basis at gigs. It's not nearly as good as the X32 in terms of remote control support or internal processing, on top of way less inputs for a much less bang for buck compared to the X32, but it's cheaper and still great overall. The only thing that you really need for the TouchMix is a tablet for remote control, as that's the only way you can get full control over the mixer. With the X32, no matter what device you run the app on (phone or tablet) you get full control. Plus a ton of customization.
If both of those are out of your league, the next best thing is a Behringer DCX2496. It's not a mixer like the TouchMix or the X32, but it has all the processing you would need, including limiters, parametric EQ, crossovers, etc. It's a system processor, so you get all the things you'd normally get with one of those. There's no wireless remote control support, so tuning the system can't be done out in front of the system if the processor is located at or behind the rig, unlike the TouchMix or the X32. But you still get all of the core features you would need.
The last, and cheapest, bare minimum option I would go with, is just a standard dbx Graphic EQ. This is pretty self explanatory, and there's nothing special about it. But it's the cheapest option available. Honestly, with the price difference between this and the Behringer DCX, I'd much rather go with the DCX.