This problem happens to be one I’m working on in the context of a more general recognition app. I don’t have an app to send you now, and you may well find a solution in the coming weeks. Even if you do find something that works, I’d be happy to have you involved in some user testing. I can’t claim any specific time frame when 7-segment OCR will be available, but it’s something I need to implement.

I was able to read my microwave’s time display using VoiceDream Scanner. One issue some OCR algorithms may have is the disconnection of the segments, in which case stepping farther back or holding the phone farther away can help.

I was also able to read the 7-segment display with VoiceDream Scanner close up, but only after I adjusted the four corners of the detection region to limit it to just the control panel.

One problem OCR apps often have is the way they automatically determine how to differentiate text from the background. This can be especially tricky for black shiny surfaces like the control panels of many appliances. In that case, one hack would be to tape other materials (e.g. white paper, green paper) around the control panel to affect how lights and darks are interpreted. (I work in image processing, so I can dive into the details if you’re interested.) Since the app may not have parameters that allow you to affect its processing, you change the image it sees and try to accommodate the app’s baked-in algorithm. This takes a little experimentation, but once you’ve found a solution—kitchen light on/off, paper or other objects of different brightness around the 7-segment display,—it has a chance of working robustly.

Finally, in the context of segmented characters, I should mention there is a counterintuitive approach that may help. If an OCR algorithm works better with connected characters, then you can help the algorithm by blurring the characters. You can’t change focus on your phone (usually), but you can try applying some translucent plastic to the display to make the characters appear slightly blurry. If you can’t find the right plastic that blurs the characters just a bit, then you might try smearing something to try the same effect. Whether this work depends on a lot of factors, and depending on your control display and lighting conditions it may be very hard to pull off, but if nothing else it illustrates that sometimes changing the object itself will help with recognition.