That's pretty cool. I've never put batteries in my RDF, and then one of the adjustment thumbscrews broke. I typically just align to Polaris, set the setting circles properly, then use SkEye on my phone to figure out where to go. It's surprisingly accurate, to the point that I'm not even sure I want to bother with a finder. But there are times when it's not so accurate (usually because I didn't align properly), and I find myself casting about for what I'm looking for. At those times, I curse myself for not upgrading the finder (or at least putting batteries in the RDF).
Yeah, OP needs to find the limiting magnitude for naked eye visibility.
Also, /u/headball123 could try my app if they have an Android phone.
I love the stellarium desktop app and this mobile interface looks great, very smooth interaction. However, one feature that is missing that, to me, is really important is the ability to mount it on a scope and configure it as a "push to" device (like skEye).
Another post here on Reddit mentioned a program called SkEye for Android. You can use it to guide your scope tube. You point your scope at a known star with your phone affixed to the tube, navigate to that star within SkEye and 'align' the program. Thanks to genius of modern phones, it now knows where your scope is pointed with a handy map. It's like a Garmin for your telescope.
As far as I'm concerned this should be a permanent link on the right side of r/astronomy for all us newbies out there.
You could try the SkyEye app. It's a push to solution using your phone or tablet to determine where the scope is pointing. Doing this with goto would be problematic due to all the different mounts using different motors, gears, and electronics that would require different drivers for each. Sky Safari probably has the more extensive goto and push to mount compatibility.
Phone cameras are principally designed for video and still images in brightly lit environments. Hence the reason phone makers started putting flash on phones. But things are looking better. Some apps can increase the exposure range of the camera if the hardware supports it. But longer exposures require a mount capable of tracking the stars more accurately than is needed for visual use. For things like the moon and planets, exposure times would be short enough to not cause blurring, in fact, video works better than still imaging for these objects as you can parse through the video, pick out the best frames and stack them together to crate an image with better detail than you can see in a single frame.