When referring to GPS related apps, checking in means "revealing your location in an online message posted from your cell phone."
Check-in is a word used in different contexts and based on this, its meaning can slightly change. Here are some examples:
The sentences that best matches the meaning of this word is "revealing your location in an online message posted from your cell phone."
Learn more about GPS in: https://brainly.com/question/1823807
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