I have been struggling for some time with low down macro shots due to an old knee injury. I can set the camera up easily enough but, because I use manual focus, I find it hard to adjust when my camera is at low levels. I was going to treat myself to a right angle viewfinder but, decided against it because they are quite bulky and it would be another big thing to carry. Instead I opted for a CamRanger which acts as a remote control. It is a little gizmo which you attach to your camera and then you can make adjustments wirelessly through an iphone on ipad/iphone. I don't have an ipad and my phone is ancient but, they have recently brought out software to use it though a Kindle Fire HD.
When it arrived I had doubts of how easy it would be to connect up and get working but, it was surprisingly easy. Charge it up, connect to camera ( a list of supported camera's on on their website) download the software to kindle and register it via a code which is on the little gizmo. All went well and I have spent the week testing it out.
When you open the application, there are various options but it works by focusing when you tap the screen. So, you tap it once for focus and twice if you want to view your subject close up. You can adjust the focus manually in the focus tab by using arrows. You have the choice of big, medium and small steps to finely tune your focus. You can alter your aperture, ISO, white balance and adjust exposure compensation from the application.

The focus adjustments are all made by switching your camera into live view. I did find this a little hit and miss. Certainly tapping the screen works in good light but, it gets more difficult in low light or areas of low contrast. However, the incremental adjustments means that you can still concentrate wholly on the area you want in focus. So, for this next image, I concentrated on the little water drop on the nearest snowdrop.

After you have taken the snap, you can click on a thumbnail within the app to study the actual photo too.
The added benefits are that you can also use focus stacking. Again you have various controls, you can choose the number of frames and also small, medium or large steps. It is best if you start at the edge closest to you but, you don't have any control of the end step. Therefore, this will be a matter of trial and error. You need to use focus stacking software to merge the images afterwards. I used CS 5 for this one and there is a great, simple tutorial on Youtube. This one was two stacked images with medium steps. I think I could have improved upon the detail at the very back of the tulip with a third image.

This application is also suitable for HDR but, I haven't got that far yet!
I did decide to see how useful it would be for wildlife shots. So, the tripod, camera and gizmo were set up in the back garden and I retired to the warmth of the kitchen to play. I found that the delay on live view on actually taking the photo was too great to be effective. So I set up all the focusing and camera controls in live view and then turned it off. I just watched the feeder to take the shots. This worked really well, despite being behind two doors, the camera response is immediate. But, of course I was focused on the feeder so, there are limitations here.

I still have a number of things to play with ~ video, time lapse and as mentioned HDR. The down sides are the cost (but it was still cheaper than a decent right angle view finder), it does seem to be a bit glitchy at times and it does seriously eat up the battery use in my camera. The plus sides are the precision, it is fun, ease of use and I am not crawling around on the ground for those low down shots. I also love being able to see everything on a bigger screen rather than looking through that tiny viewfinder. If I think or come across anything else, I will add to it