Many third-party Instagram apps have ceased working with the service following the rollout of new rules affecting API access. As noted by MacRumors, the stricter rules governing API access officially went into effect on June 1, severely limiting or rendering useless many third-party Instagram apps.
Gramfeed, for example, has updated its website with the following message:
Goodbye! As of June 1st 2016, Gramfeed will no longer function. To conform with the Instagram API Platform changes, Gramfeed had to be transitioned to a new service called Picodash and is focused on providing the search and social media management functionality to brands, publishers and journalists.
For some background, the move follows the revelation in late 2015 that a third-party app called InstaAgent was harvesting usernames and passwords from its users and storing them on a remote server. The app was also found to be posting unwanted photos to users' feeds.
In response, Instagram opted to severely restrict API access for third-party apps, and began reviewing apps in December before granting access. Apps that were created before November 17, 2015 were given a bit of a grace period, with the new rules going into effect as of June 1.
For more, you can read up on Instagram's new platform rules on the company's developer site.