From the short time I had my M8. I could back up my settings (for the phone not apps) and contacts via my gmail. But I had to make sure that my gmail was selected as the source to back it up. If I added a new number it'll give me a option save to phone or gmail. If you don't select your email your either SOL or I hope you have a good memory if in the case you need your phone replaced. Now when it comes to photos that relied on the phone maker. HTC had their own backup system for your photos, apps and etc. I would assume that Samsung, lg and whoever else makes android phones have their own system on backing up your info. Idk if Google has their own all in one backup similar to iCloud.
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