I guess other important point is to store originals as well (or maybe even rendering originals directly). and also RAW format for audio video.
then comes question on handling 250GB+ videos and libraries for TBs sizes
Apple Photos rocks in all of the above. and it also works excellently offline.
to beat it you have to really solve those problems..
As far as "beating" Apple, I'm ready to bet that'll never happen (not just with this project but any really). A small open source project can't really compete with a $2T company
Two bugs stood out to me immediately:
1. Tapping on the i button does nothing.
2. After clicking around on some images, the back button was mostly useless until I pressed it like 10 times. I think it works for album navigation but stops working when you start photo navigation.