Existing apps

Litere Numere Culori Gratuit

https://play.google.com/store/apps/details?id=com.weplaywelearn.romanianletterpairsfree Review from Hannah:

I tried one of the apps you found (the second one - ugly but useful) with Cezar (the smallest of the boys from the Delta) and it was very good What worked well is that it said the name of the number or letter and the child has to find the right letter from those given.