Locket Widget has topped the charts as one of the most popular iPhone apps, and it's managed to do so as a 100 percent free application. Since its launch in January 2022, Locket's proven to be an app people can't get enough of. It allows users to share photos with each other similar to Snapchat or Instagram. Unlike those apps, however, Locket users can only interact with up to five other people at a time. Furthermore, photos are shared directly to other people's home screens — making the experience much more personal and unique.