Earny - Automatically Get Refunds for Price Drops
Earny is a free app for iPhone and Android that tracks your purchases and then automatically asks for a refund when there is a price difference. Earny keeps 25% of the price difference and you get a check for the rest. It's frictionless and once you set it up you don't need to do anything.
With Earny you will need to link your email address. You can also link your Amazon account and your credit card account if you want to amplify the options to make money when prices drop on something you bought.
While you can do all the tracking on your own and ask for refunds Earny does all of this without you spending any time and you get the bulk of the savings.
If you sign up through this link you can get a $5 bonus. You can then download the app for iPhone or Android.