I’ve tried them all, this is the keeper. I use it for a gallery of multiple genres and multiple artists. Killer features are: 1) Photos retain their filenames as on the Mac; 2) You can sort by multiple criteria including filename; 3) You can nest subfolders; 4) You can select a photo for the cover. Esthetics are important also, and this one looks quite nice with the black background option. Cut to the chase and buy the pro upgrade for data loading, it’s fast and accurate. Note, the app doesn’t back up to iTunes, so photos added originally in the app need to be archived separately. They offer a backup service, but it’s not in my use cases so no comment. I maintain everything on a laptop as the original source, but I can export anything to the laptop if I add it in the app, thus the value of filenames and metadata. My only quarrel is the passcode format – a 4-digit PIN would be a convenience, not a deal breaker but if fixed would rate a sixth star...