Backup and restore options

[GEkuL]

It would be great to have backup and restore options. This would be useful for those changing devices or simply changing ROMs

For example simple json/csv files for that purpose.

[dawidmachon]

I would like to see:

• import as paste plain text, each product, each new line. It will be very helpful to paste from SMS or website.
• export as plain text, each product, each new line.

Originally posted by @dawidmachon in #31 (comment)