Meanwhile, we keep working towards to improving our user experience on all the devices especially the lower-end ones (I personally use iPhone 6 as my go-to test device). For instance, we will add caching very soon to shorten the interaction waiting. Hopefully you will enjoy more using Discord on your SE then :)
If we had some magical way to make the dev treadmill run slower than the user treadmill, we'd see better architectures in many cases. In that alternate world it would be easy to precompile the javascript and load 20 times faster.
iOS users tend to run newer devices generally which might lead some devs to feel that this extra optimization isn’t worth the time it takes, but I disagree because it doesn’t benefit only users with older devices – it’ll make your app run better on newer devices too and make it that much more unlikely that your app gets killed or causes the OS to kill other apps in multitasking scenarios (iOS kills resource hogs much more readily). In short, everybody benefits.
With this same thought process, I plan to pick up one of the 120hz iPad Pro models to test on soon. It’s one of the most powerful iOS devices available, but driving 120FPS isn’t easy and given how many apps fail to hit the target of 60FPS on similar hardware I’d bet that a huge number, perhaps even most, don’t come anywhere close to running at 120FPS even with the extra horsepower.
I've seen startup latency much slower than that on my iPhone SE. In the best case, the application takes about six seconds to cold boot when I tap on a notification. Sometimes it's closer to fifteen or twenty seconds if the app sits on the "connecting" screen for a while. It's difficult to understate how much slower the app feels than everything else on my phone.