Small business owners have many times more complications when required to collect and save receipts. Pikki is an iOS app will digitally save and organize your receipts. These are sufficient for storing and doing you taxes. You can store away or lose the paper receipts. I have been working to go fully electronic for years but have been only able to get to about 80-90%. An app like this will get you closer to digital tax Nirvana.
If you want an always free way to do this on Android then you can use Google’s Instant Upload which will take every photo and upload it automatically to a folder that you can arrange later. This is not as convenient as the Pikki solution but gets you there.