I absolutely despise the fact that all sections are collapsed on load on mobile. That means "search in page" is broken and Wikipedia without search in page isn't Wikipedia at all.
It's iPhone's number 1 unknown feature. I've been using computers since I was two and it took me more than a year to find this: just type in the search term in the safari search bar, then scroll down in the autocomplete results (without hitting go or enter). It'll come up after autocomplete and history/bookmark matches - and it's been there since at least iOS 6.
Before this, when iOS had separate search and URL boxes, typing in the Google search box would offer a prompt to search in the page since ... maybe v3 was it? Hence why that moved to the URL box when the boxes merged. Yes, it sucks.
The other one in a similar vein is pulling the search results down (before typing anything) to get 'Request Desktop Site'. It took a while before I stopped having to pause to remember where that was each time I wanted it.
