Free, Great selection, High resolution, Easy navigation, Simple, Reminder to give photographers credit
Some common keywords are lacking (TOTALLY understandable), Sometimes images are hidden in "collections", some clutter w new features
Unsplash is an amazing resource. When I started designing/developing purchasing expensive stock photos was one of the only ways of consistently getting images to use in design/web projects.
With Unsplash and Pexels, etc. though now I have access to an almost unlimited library of images. I've used Unsplash for projects all the way from mobile apps, websites, to billboard advertisements. Best part is I can just sent my clients the link and they can browse through the images themselves and send me the ones they like.
Overall an AWESOME resource. There are some minor annoyances like the addition of features that I feel just add clutter and don't add to the core value proposition (but that may just be me, and I won't name them so you can form your own opinion). My FAVORITE feature though is where they suggest giving the photographer credit - SO important and underrated.
When you have people providing as awesome resource as this it's only fair to thank them. Unsplash is a fantastic site and I highly recommend it to everyone... My one gripe is that I don't think they need to keep adding features.