Also you can configure s3 buckets to delete files older than X days. For non critical projects I tend to set this at 30 days. This way the total storage used by the backups doesn't grow beyond a certain limit and helps you to control the spending.
My app makes roughly around $1K/month. A simple utility to backup(free) and restore(paid, in-app purchase) mobile phone contacts.
Check it out: http://c2x.eastros.com/
I only know for Android since that's the only mobile OS I have ever used so excuse my question if it sounds stupid:
Why should I pay for your app if Android has a built-in backup/restore system for contacts? Or does this work by creating backups periodically in case you accidentally delete a contact you might not have wanted to?
Good question, and there are couple of reasons why people buy the import feature.
(1) If you are switching from Android to iOS or vice verse, app can make the contact transfer process very simple and convenient.
(2) People like you and me can find very easy ways to transfer contacts, but there are a lot of non technical people who don't know about auto backup and restore features.
Experienced Backend Engineer, love to do everything that happens on the server side, including architecture design, data modelling, business logic implementations and rollings this out.
