There's a swing weight app for your iPhone. It works the same as the manual method described in TW University. You have to know your rackets weight, balance point, and then you hang it from a table on 2 pencils and let it swing. Point your iphone camera at the handle and push start. Based on the TW manual customization tool, it is accurate if done correctly. You'll also need a good measuring tape as you have to enter distance from pencils to end of butt. You also need a gram scale to weigh your racket. You can use the end of flat table as a balance board. The app cost about $2 or $3.
By the way, if you buy rackets from TW, have them give you 2 matched rackets. They match 2 rackets for me with exact balance and swingweight - charge $10 per racket but it is worth it. The static weight was about 2 grams apart. Basically, they are over 99% the same - within 1% margin which is very good. If you know the beginning attributes and have a matched pair, you can use the TW manual customization tool to see how lead will impact weight, balance, and swingweight.
You can do it yourself if you want but it will take a few bucks and some time.