Just wanted to shout out
Flightmatic here, probably the most clean and modern looking logbook app I've seen on iOS. I have no affiliation to it, was just browsing logbook apps to see if any new ones had popped up. It seems to be developed by one person and it is still pretty basic at the moment. I noticed the odd spelling mistake here and there. And it does not have the advanced features and reports like LogTen Pro et al. If you don't need anything really fancy, it will probably do the job pretty well. I just appreciate the clean UI and hope it can grow into a contender.
RB Logbook also seems worth a look, mostly for the RosterBuster integration if your airline roster system is supported.