it would be perfect if you add an option like writing on the images

Yes, this would be a great feature and we are definitely considering adding it to Meld. We'd recommend using other type overlay apps (that are made especially for it and therefore do it well) as part of your workflow - there are a number of apps available some of which are free on both iOS and iPhone. We'll keep you posted if/when we add this to the Meld dev roadmap.