Progressed Synastry as Important as Natal
I've been developing Starlove for about 10 years now, it's currently in 25 languages and has been downloaded about 2 million times. Busy planning a web service that will hopefully connect LED badges via Bluetoothto their phones and the net that display how compatible you are when you meet someone at, say, a club that is standing in front of you. The LED badge will display red, amber or green based on the Starlove algorithms in the cloud. So when you are in the proximity of someone (the closest person) you know how compatible you generally would be with them, if you both have the Starlove app enabled at the time. Still trying to find Bluetooth technology that is not too expensive to apply as I want the badges to be very cheap to manufacture. You can get the related tech that does things like open your garage door via your cellphone using Bluetoooth but currently a bit too expensive for to implement.
During this time I realized that progressed synastry is at least as important as natal, mainly because it's your current situation. No good having a wonderful natal synastry if your current is all viciously messed up, and as you know, progressed aspects can last many years. Most synastry software does not even take progressed synastry into account. For example, my sister and her first husband had great progressed synastry back in 1985 when they met and got married. Their natal is average, current progressed is terrible: they now hate each other with a passion. I think this kind of thing happens with a lot of marriages that fail.
Wishful thinking, but a fun idea to create. It works pretty well... enough to base a marriage on based on most of the unhappy marriages I've checked out. For example, see how Starlove gives Brad and Angelina a clear avoidance rating and accurately predicted the two years that they split up: http://www.luckydays.tv/StarLoveSetup.exe - I see they are now kind of together again and you'll see how the progressed let up on them to at least enable them to bear each other or work things out to an endurable extent.
Even general Sun sign compatibility (which is also built into the algorithms) can be most helpful when looking for partners: http://www.luckydays.tv/zodiac-compatibility.html
My new website is StarLoveMatch.com which aims to help dating websites find the most compatible matches for people based on their birth dates. You can test it yourself by entering the birth dates of people you are close to.