Although translated to Bulgarian at crowdin (several updates ago), the iOS mobile app still has lots of crucial text left untranslated in English: observe, camera, camera roll, more, edit, back, cancel, done, (for coordinates) lat, long, acc., <number-of-days>
d, <number-of-months>
mo, <number-of-years>
y
The taxon ranks in the Suggest ID dialog: family, subfamily, etc.
In the Leaderboard: observations, species
Most of the strings do not exist in crowdin; some do - and are translated - but are apparently not used at least in some places.