You can do this for free if you have a device, like a phone, that supports usb otg (on-the-go). There are various apps that are free and all you need is a usb otg cable for your phone, you can usually get them on ebay for $3-4. Now if you want to go wireless then the CamRanger could do that, but you are still going to have to connect the CamRanger to your camera. I have several apps on my Android device that do this now and there are apps available for iOS as well.
For more information just Google
android dlsr remote
or
iphone dslr remote
Or just check the Play Store or iTunes for dslr remote.