Image classification using MIT App inventor

Good morning,

I am working on developing a currency identifier application using MIT APP Inventor.
I came across two extensions, LookExtension and PersonalImageClassifier, mentioned in the link below. Image classification. I tried the LookTest.apk on my phone, and it works. I could identify simple objects like a wallet and a mug. However, when I used a currency, the extension did not identify it correctly. Is there a way to train the extension to recognize more objects?

Thanks in advance for your support.