Hi, I am new to tapas but I have gained some knowledge by trial and error. I hope I can share it with you all and I hope you guys can do the same... let's work and help each other, for the time being here is some info on how to make those annoying speech bubbles and some cool software to do that.
Have you tried using the software Krita? it's free and very powerful... it comes with typing and you can also make speech bubbles!! If that doesn't work try using Paint on Windows 7 or for better results windows 10 Paint which comes installed on your computer. let me know if this helps as I have other suggestions.
happy to help,
Dest Pantheros