If you use your iPhone or iPad to take video & pictures and you don't hold the device correctly (volume buttons pointing down, round Home button on your right), you'll end up with upside down or sideways images.
http://iphonephotographyschool.com/iphone-photos-upside-down/

Apple has auto correction software in its iOS devices to compensate for this. But other devices do not.
You seem to have the opposite problem, however. Looks OK on other devices; upside down on iOS which means your image still contains Apple's orientation metadata.
The best strategy is to open images in Photoshop. Rotate as needed. Export As JPG or PNG with a new filename. Set Metadata to none. Also don't forget to adjust the quality slider & scale to reduce file size. Raw images are typically way too big for the web.