what is the difference between feature add-ons and features purchased with flex bucket funds?

The difference is how you pay for these services. Features or services that you “add-on” to your plan appear as a monthly recurring charge on your Cricket bill. Whereas with Flex Bucket, you simply purchase funds as needed.

For example, if you have roaming minutes added to your plan each month as an add-on, and you use all of your roaming minutes, you would then have to purchase Flex Bucket funds in order to gain additional roaming minutes.

All products available on the Cricket storefront require Flex Bucket funds to pay for them and may not be added to your monthly bill.