Picturando is a photo editor online that works on mobile and desktop. You can easily resize, crop, merge and transform your images.
You can crop photo to one of specified aspect ratios or select your custom crop zone via editor interface.
Moreover, the editor has additional features (like merge photos) and filters like grayscale, blur, black e white, vintage, adding frames to photo, corners and more. All objects can be filled in with many built in or custom patterns and gradients. Like Photoshop, all editor actions are non destructive and can be easily undone and redone via history tool. And, last but not the least, this editor is completely free!
Instructions: To resize or crop your photos, simply upload it (icon open, as background image or overlay or image to merge), select functions you need (very intuitive). When ready, simply click on "Save" to download your final photo montage.