I'm about to start developing an app, and I will say, that the only thing pushing me away from Adalo is the fact that it doesn't give me any of my source code. With one other complaint I've heard about Adalo being about it possibly being slow, I can't be confident that I'll be able to go through my source code and actually be able to make it more efficient if I need to by 'going under the hood'

I would even buy my source code, it would make this a truly perfect site, but until then I don't think I can confidently use it knowing that it's trapped with you forever...

You've already got me wanting to stay here because of UI and UX, so you don't need to trap the code.