Boomerang is a free lifestyle app designed for Android users that rewards users for submitting payment receipts. Users can earn points by simply photographing any receipt up to three times a day. Additionally, when shopping at participating stores, users can register their receipts to receive a percentage of their spending back, with varying cashback rates depending on the store. The app also features options to locate nearby participating stores and includes a daily attendance roulette for extra point rewards.

Users can invite friends to join the app, allowing both parties to earn points when the invited friend accumulates rewards. Accumulated points can be exchanged for gift coupons through the app’s point shop. The app requires optional permissions for camera use and location services to enhance functionality, but it remains usable without granting these permissions, albeit with some limitations.