There are many different accents within the English language. Even within American accents, for example, there are many regional differences. Someone who grew up in New Orleans will have a distinctly different accent than someone from Boston or Los Angeles. Most TV newscasters use what is called the “General American” accent, one that isn’t identifiable as coming from any specific region.
The broadcasters on BBC news in Great Britain use what is called “Received Pronunciation,” an accent derived from the south of England. People from different parts of the UK have their own regional accents.
Regional influences similarly affect native English speakers from New Zealand, Australia, South Africa, and other countries with large populations of English speakers.
Because Lingokids is used by children around the world, there are a variety of accents in the app. It is important that children be able to follow various accents when using receptive English (listening). When speaking (productive English), they may use a slower pronunciation (and accent) that is affected by their primary language. Young learners are flexible and can adapt easily to hearing differents accents, which is good practice for English proficiency.
For examples of the variety of accents around the world, the following links are useful:
21 accents: https://www.youtube.com/watch?v=3UgpfSp2t6k
17 British accents: https://www.youtube.com/watch?v=FyyT2jmVPAk