Being a linguist, you often have to transcribe things in IPA. Out of several languages you work on, there would be times when you work on only one language with a limited inventory of phonemes. In such situations, when you are writing the transcription of a word in a language using IPA, you will often have to write characters like ɘ ɛ ɪ ʃ ʈ ɲ ɳ ŋ ɖ  ̃ ʰ and so on. While there was a time people used fonts, with advent of Unicode and existing font sets including the IPA extensions, it is now easy to use the Unicode which would be visible on any device, without installing any fonts.