There are two different things you will need, the first is a USB OTG adapter. In its normal mode, the phone is designed to act as an 'accessory' to a lot of devices (e.g. memory card for the PC), a USB OTG adapter (may have even come with the phone) creates a USB female port, and tells the devices connecting to the phone that the phone is acting as a 'master'.

Check with your device, as some do not allow host mode USB. My understanding with qDLSRDashboard (I use this on android) is that it does not work via USB to DSLR camera's due to limitations on the camera connection kit.

It does work on Samsung Galaxy devices, but it is much easier to use on a bigger screen (e.g. if i use it on my samsung galaxy S7, the screen is very cramped, whereas my Galaxy Tab S2 is much easier to use it on)

There are other ways to use it via the mini, you might have to have a look but my understanding is you can use a very specific brand of portable travel router to kind of 'bridge' the devices via WIFI, and the camera via USB to the router.