You can think of Smart Kit as a kind of collection of all the applications that might come in handy at different moments. This way, you have them all on hand so you don't have to download them one by one whenever you need them. They are all offered by the same application, Smart Kit, so they have the same aesthetic and are located in the same menu to make it easier to access and identify them.
You can find everything in Smart Kit: a note pad, a translator, an application for tracking exercise, a cloud for streaming music for free, a smartphone file manager, a metronome, a voice recorder, a flashlight, a mirror, a magnifying glass, a barcode scanner, a checklist, a device cleaner, a calculator, a calculator for currency exchanges, a ruler, a speedometer, and even a way to check your pulse.
You probably never thought you'd be able to find so much in just one application, but this application is full of useful tools that will get you out of a pickle on more than one occasion. It might never have occurred to you that one day you'd need a level or a measuring tape until the moment when you realize you don't have it. So with Smart Kit, you can forget about feeling that way and have a kit with various different tools, all of which are sure to come in handy sooner or later.