I'm using Alby Desktop, which is a self-custodial lightning node for desktop computers. I really like it, but they don't have a mobile version afaik. I think a mobile version of something like it would be really great. I tried Breez before, which was also a self-custodial mobile lightning wallet but it was a bit buggy for me.

I also think something has to be done about routing ease-of-use in lightning. Routing failures appear quite common unless you're willing to pay high routing fees. Problem is, it's not obvious at all what the "correct" fee rate is in order to make a lightning transaction.