The Secure Folder app which first debuted on the Galaxy Note 7, leaked this morning for the Galaxy S7 and it actually shows some images of a smartphone we haven't seen before. It shows what many believe to be the outline or silhouette of the upcoming Galaxy S8. Typically in app listings like this, manufacturers like Samsung, will show off their most recent flagship device (which in this case would be the Galaxy S7) instead of just a standard screen which appears to be what we have here. However, the design also looks very similar to the Galaxy S8 leaks that have surfaced as of late.
In the pictures that are part of this app, you'll see a device with some fairly small bezels, with the largest one being at the top where the earpiece is housed. Recent leaks have pointed at the fact that the Galaxy S8 is going to be about the same size as the Galaxy S7, but with a much larger display, due to the much smaller bezels, and this outline of the device fits those leaks perfectly. This would also mean that the physical home button is going away, likely going towards software buttons. Something that Samsung has never officially done, but they were on the Galaxy Nexus (that was Google's design choice though, not Samsung's).
The Samsung Galaxy S8 is said to be skipping Mobile World Congress this year, at least according to Samsung executives. They haven't announced when the device will become official, but many are looking towards a separate event at the end of March or in April. Samsung also reportedly has an exclusive on the Snapdragon 835 chipsets until then, seeing as Samsung is manufacturing the processors, it appears that they are getting first dibs. Along with the Snapdragon 835, the Galaxy S8 is said to have a Quad HD Super AMOLED display, 4GB of RAM (or 6GB, depending on the leak you look at) along with at least 64GB of storage onboard. It's bound to be a pretty spec heavy device, which is pretty typical for Samsung. And this time they will have performed many battery tests on this device before hand.