I don' think either sentence is correct. I can't understand what you mean by 初の.
Do you mean, "This is the first application Mr. Tanaka introduced to me."? If so, you can say like this;これは田中さんが私におしえてくれた最初のアプリです。
By using おしえてくれた instead of おしえた, you can express thanks to Mr. Tanaka.