Ypu can use the Pinyin trainer - there you get a good overview and can exercise the different tones and the way Pinyin is used to describe the Chinese sounds.
The pinyin trainer is available both on iOS and also on Android = you can find it on the store or use the following links:
https://play.google.com/store/apps/details?id=com.molatra.pinyintrainerlite
or
https://apps.apple.com/us/app/pinyin-trainer-by-trainchinese/id376797304