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Apple App Store and Google Play Store are loaded with hundreds of apps you can use to like photos, earn "coins," and spend the coins to buy likes. Find one of these on the App Store or Google Play Store by searching keywords such as "Get likes," "Get likes for Instagram," or "Instagram likes". However due policy changes in Apple and Google stores, these apps are no longer available because they were stealing credentials to Instagram accounts, but there is legitimate app offering similar experience, called "Matez". It does not need your instagram password, it is secure and it's conforming to AppStore terms and conditions. Look at reviews of the app. Decide which ones are most reliable. After selecting an app, download it.  Apps usually have a skip button, which can be used to skip photos you dislike. Beware that the app may not deliver 100% of the likes you buy.
Use other applications. Download an app. Log into your Instagram account. Start liking other people's photos. Spend your coins on likes you want.