This app was mentioned in 7 comments, with an average of 3.00 upvotes
In order,
太爺
太嫲
太外公
太外婆
外太公
外太婆
外太(外)公
外太(外)婆
For more you can refer to this app on Google Play and possibly Apps Store as well, its basically a "calculator" for tracing all of the names of different relatives.
http://www.mandarintools.com/family.html I have used this since I was a kid (or at least, since I learned to use the internet) and it is very straightforward.
There is also the android app 三姑六婆 here - https://play.google.com/store/apps/details?id=com.blogspot.relativescalc although handy in a pinch I find it sometimes a bit complicated to use when it comes to further relatives.
Anyway, have fun, it's a fucking nightmare trying to figure out what to call relatives at Chinese New Year and this has saved my ass a couple of times.
https://play.google.com/store/apps/details?id=com.blogspot.relativescalc
Yes of course there's an app for it
Time to introduce the 親威 calculator.
https://play.google.com/store/apps/details?id=com.blogspot.relativescalc
Wow this is amazing. How did I not find this?
Android link:
https://play.google.com/store/apps/details?id=com.blogspot.relativescalc