Either I use hacker's keyboard or gboard, and with both I constantly misspell things and miss the keys. In online IDEs which do have some sort of autocomplete it tends to cover up half the screen. And with the other half is covered by the keyboard I can't see what I'm picking or writing or the context.
Something like an auto complete with an auto-zoom in and out when I type or choose something from the autocomplete would be nice.
Also some conveniences for copying and pasting lines of code around, not by using gestures (I'm clumsly...) but through a combination of keyboard and/or on-screen prompting.
This is a rather niche, since like I said I usually don't code on my phone. The only time I felt it was missing was when 2 years ago I did Advent of Code on my phone during commutes, and the only site that worked for me was ideone.com because their text entry is essentially just a simple no-frills textbox. So I didn't have autocomplete but I could bang up a reasonable solution in a reasonable time (I tried to get a semi-decent score).
2) I wish there was an easier way to view forks / branches of a given repo, across all popular sites. This would help finding forks with fixes of a repo which looks abandoned.
3) A site which aggregates book reviews from various sites, similar to RottenTomatoes but for novels.
Currently when I'm searching for book reviews when considering to buy or listen to a book, I first read (non-spoiler-y) reviews on Amazon, then on GoodReads, then google for reviews on various online outlets, then google for blogs, and maybe even search Youtube if I have the patience to listen.
There's https://bookmarks.reviews but it doesn't have too many reviews on it and of course doesn't include Amazon's ratings.
Something semi-automated would have been nice. For children's books it would also be nice if it included reviews from the CommonSenseMedia and Children's Book Council of Australia sites.
4) A way to browse all comments for a youtube video.
There's https://youtubextras.com but it doesn't seem to work for me.
Jump to a certain time and view comments from that time period.
Not just download them, browse them in the browser.
I know many people don't like youtube comments but I sometimes find them hilarious or even insightful (especially on popular dev-related videos), and I don't like youtube's interface for browsing them.
Something HN-like would have been nice, something that will figure out who is replying to whom in the flat second-level hierarchy and nest them. Possibly a browser add-on.