Does a good job - but ads are too intrusive

This app was good until sometime in 2016 when the frequency of the ads increased and became so intrusive that learning isnt possible anymore. The price for the PRO version is priced far too high for a simple utility. If this app is the gateway for customers to explore the developers other software, I believe they are hindering their sales by this strategy. I have given up on this app in its new advertisement-bloated form. It was good for many years.

21tesla about Pinyin Chart - Learn Chinese, v3.6