I do exactly what you're wanting to do with
this kit. Unfortunately, the kit and the Light Probelinc itself are discontinued. However, you can still buy I/O Lincs (
here, or at Smarthome) and can still find some Light Probelincs
on eBay. It works for me quite well, though not without some customizations to the adhesive. The included adhesive is way too big and would cover other indicators and buttons, so I removed it and used electrical tape to block outside light instead. The Light Probelinc is least sensitive to greenish light, so if your washer and dryer use green LEDs for the "Done" indicators (like mine do), you have to be particularly persistent in blocking out all other light with the electrical tape. If your digital washer and dryer use an LCD status message instead of an LED indicator, this setup won't work. An iSync Solo could work with a washing machine. If your dryer is gas powered, an iSync Solo would likely work for it too.