Here is an easy way to use your Android device to view images captured with a normal camera. You just need an OTG cable (see image below. You can get one for as little as AUD$1 on eBay). You would also need a card reader.
There are several image viewer apps you can use. I use the built-in "My Files" app. This app helps you to navigate around files and folders like you are used to on a PC. You can download any image from the USB/OTG-connected storage, and then "share" it via Gmail, Facebook, etc; or download selected images on to your Android.
Here is the step-by-step instruction. Remove the memory card from your camera and plug it into your card reader. Use the OTG cable to connect the card reader to your Android device. Open up the "My Files" app and click on the USB folder. You can now start to view your images.