The PlayStation mobile app is terrible- it’s not quite as bad as Nintendo’s app, but it’s still been slow, clunky, and basically just utterly useless (especially ever since Sony split out the Communities and messaging functionality from it into separate apps) for a while now.
Thankfully, it sounds like Sony’s trying to fix that. They have released a brand new update for the app, which gives it a face lift and updates its UI, from being less like it is on PS4 to something more suited to a touch screen enabled smartphone. It’s unclear whether this will make it any more useful than it has been- but at the very least, it won’t be a total pain to use anymore.
The update should be available on the App Store (if you are on iPhone) or Google Play (for Android devices). Hopefully, Sony continues improving its mobile app in the days to come, too.