For practically any non-Asian person, learn Chinese it can be very difficult. One of the reasons is that Chinese is a tonal language, which means that for what we would believe to be the same word, it actually has different meanings depending on the tone used. I know cases in which people have joked with Chinese people to speak in their language and they have even said "you speak like a baby" implying that we speak their language with a lot of imprecision because we do not use the correct tone. In one tone, the word "ma" can refer to her mother and, in another tone, it can refer to a horse.
Furthermore, Chinese writing is based on a pictographic system (very different from the alphabetic system) and the words are not made up of letters, but are represented by pictures, which further complicates things are the different dialects of different Chinese systems, such as pinyin, traditional Chinese and simplified Chinese. The most widespread Chinese dialect is Mandarin and the list of applications that we will propose will focus on it. Traditional Chinese or Mandarin.
From the following list there are paid and free apps. In the list I have also added applications that are only available in English, in case you also master that language and you prefer those applications to the ones on this list that are in Spanish.