Stock photos and image optimizers
If you're looking for stock photos free for both: individual and commercial use, then you should try the Pixabay. Pixabay doesn't limit you. You can download as much pictures as you want, except extra large files. You don't need to register yourself, if you don't plan to get only medium and small dimensions.
Furthermore, ckeck Gratisography, StockSnap.io, Isorepublic, Unsplash, Realistic Shots, Life Of Pix, Snapwire Snaps, Travel Coffee Book. If you want a paid stock photography company, you can just use a search engine.