While researching the a7R, I had to use Sony's App store to check out this feature. All my news is good in that Sony is working on improving their Apps. For example, when I first used Smart Remote Control I was overjoyed that it would work on my iPAD mini. It was tremendously convenient to have a large screen for focusing and composing images. For macro work it was nice to put the camera low to the ground and position it without having to hunch down and get close to the tilted LCD screen. However, when I found that the first release of that software would not save RAW files to the camera's memory card, I abandoned it.
Well, I revisited the Sony App store and found that they updated and improved the program. Most importantly, they allow the saving of RAW files to the camera's memory card. You cannot just save RAW files however. They require you save RAW + JPEG and I presume this is necessary so that the JPEG could be uploaded, wirelessly, to either a tablet or a smart phone. For what it is worth, I find the mini tablets and tablets to be preferable remote firing devices since their larger screen provides a beautiful preview of the subject. Also, I never upload the devices wirelessly as the time used for the transfer prevents me from doing a follow up shot.
Although I have the cable release for the a7R, I find that I hardly use it. The Smart Remote Control app will work with smartphones. It seems I always forget to take my cable release, but I never forget my smartphone. Considering that the Smart Remote Control is free, it is well worth getting.
Another nice thing about the App store. They keep track of the Apps you have downloaded to your camera. So, if you have to do a total reset of the camera's settings and values (this wipes out the apps) you can download replacement apps at no charge.
One final note, you are not penalized if you buy a new Sony camera. In my case, I had downloaded the time lapse App for the NEX-6. For a time this was unavailable for the a7 series of cameras. Well, it recently became updated to work with these cameras and I was not charged when I upload it to my new Sony camera.